0000929008-23-000019 | 10-Q | XBRL Viewer

REVENUE Shipping and Handling Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Cost of goods sold	$ 4,503.1	$ 4,294.1	$ 8,816.5	$ 8,177.2
Shipping and Handling [Member]
Cost of goods sold	$ 79.1	$ 76.5	$ 156.0	$ 144.1

EMPLOYEE BENEFIT PLANS (Notes)

6 Months Ended

Jun. 30, 2023

Retirement Benefits [Abstract]

EMPLOYEE BENEFIT PLANS

9. EMPLOYEE BENEFIT PLANS

The following table sets forth the components of net periodic pension (benefit) cost for the Company's defined benefit plans:


	Three Months Ended
(In millions)	June 30, 2023		June 30, 2022		June 30, 2023		June 30, 2022		June 30, 2023		June 30, 2022
	Domestic Plans(1)				Foreign Plans(2)				Total
Service cost	$	—	$	—	$	1.2	$	2.1	$	1.2	$	2.1
Interest cost	0.6		2.1		2.9		2.3		3.5		4.4
Expected return on plan assets	(0.6)		(3.5)		(3.0)		(4.2)		(3.6)		(7.7)
Recognized actuarial gain(3)	—		—		(0.3)		(0.2)		(0.3)		(0.2)
Net periodic pension (benefit) cost	$	—	$	(1.4)	$	0.8	$	—	$	0.8	$	(1.4)


	Six Months Ended
(In millions)	June 30, 2023		June 30, 2022		June 30, 2023		June 30, 2022		June 30, 2023		June 30, 2022
	Domestic Plans(1)				Foreign Plans(2)				Total
Service cost	$	—	$	—	$	2.4	$	4.3	$	2.4	$	4.3
Interest cost	3.2		4.2		5.7		4.6		8.9		8.8
Expected return on plan assets	(3.0)		(7.0)		(6.0)		(8.5)		(9.0)		(15.5)
Recognized actuarial gain(3)	—		—		(0.6)		(0.4)		(0.6)		(0.4)
Net periodic pension (benefit) cost	$	0.2	$	(2.8)	$	1.5	$	—	$	1.7	$	(2.8)

(1) Defined as the Anixter Inc. Pension Plan, Anixter Inc. Executive Benefit Plan, and the Anixter Inc. Supplemental Executive Retirement Plan.

(2) Defined as the EECOL Electric ULC Retirement Plan, the EECOL Electric ULC Supplemental Executive Retirement Plan, the Pension Plan for Employees of Anixter Canada Inc., and various defined benefit pension plans covering employees of foreign subsidiaries in Europe.

(3) For the three and six months ended June 30, 2023 and 2022, no material amounts were reclassified from accumulated other comprehensive income into net income.

Service cost is reported as a component of selling, general and administrative expenses. The other components of net periodic pension (benefit) cost totaling net benefits of $0.5 million and $3.5 million for the three months ended June 30, 2023 and 2022, respectively, and $0.7 million and $7.1 million for the six months ended June 30, 2023 and 2022, respectively are presented as components of other expense, net.

The Company expects to contribute approximately $7.0 million to its Foreign Plans in 2023, of which approximately $4.3 million and $6.7 million was contributed during the three and six months ended June 30, 2023, respectively. The Company does not expect to make a contribution to its domestic qualified pension plan in 2023 due to its overfunded status.

Other Employee Benefit Plans

Wesco sponsors defined contribution retirement savings plans for the majority of its employees in the U.S. and certain employees in Canada, which provide employer contributions.

Wesco incurred charges of $21.5 million and $14.9 million for the three months ended June 30, 2023 and 2022, respectively, and $42.9 million and $33.0 million for the six months ended June 30, 2023 and 2022, respectively, for its defined contribution plans.

Wesco Distribution sponsors a non-qualified deferred compensation plan (the “Wesco Deferred Compensation Plan”) that permits select employees to make pre-tax deferrals of salary and bonus. Employees have the option to transfer balances allocated to their accounts in the Wesco Deferred Compensation Plan into any of the available investment options. The Wesco Deferred Compensation Plan is an unfunded plan. As of June 30, 2023 and December 31, 2022, the Company's obligation under the Wesco Deferred Compensation Plan was $26.6 million and $20.3 million, respectively, which is included in other noncurrent liabilities in the Condensed Consolidated Balance Sheets.

Compensation Related Costs, General

Other Employee Benefit Plans

Wesco sponsors defined contribution retirement savings plans for the majority of its employees in the U.S. and certain employees in Canada, which provide employer contributions.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480794/715-70-50-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480482/715-20-55-17

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (q)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (l)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//715/tableOfContent

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (o)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (p)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480126/715-20-S99-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 60
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480266/715-60-50-3

+ Details

ORGANIZATION	6 Months Ended
ORGANIZATION	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION	WESCO International, Inc. (“Wesco International”) and its subsidiaries (collectively, “Wesco” or the “Company”), headquartered in Pittsburgh, Pennsylvania, is a leading provider of business-to-business distribution, logistics services and supply chain solutions.

SCHEDULE OF EARNINGS PER SHARE, BASIC AND DILUTED (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share [Abstract]
Net income (loss) attributable to WESCO International, Inc.	$ 193.1	$ 197.1	$ 220.7	$ 181.2	$ 390.2	$ 401.9
Weighted average common shares outstanding used in computing basic earnings per share (in shares)	51.3		50.7		51.1	50.7
Common shares issuable upon exercise of dilutive stock options (in shares)	1.1		1.5		1.3	1.6
Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share (in shares)	52.4		52.2		52.4	52.2
Diluted (in dollars per share)	$ 3.41		$ 3.95		$ 6.90	$ 7.15
Basic (in dollars per share)	$ 3.48		$ 4.07		$ 7.07	$ 7.37
Net Income (Loss) Available to Common Stockholders, Basic	$ 178.7		$ 206.3		$ 361.5	$ 373.2
Preferred Stock Dividends, Income Statement Impact	$ 14.4		$ 14.4		$ 28.7	$ 28.7

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-7

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-10

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 16: http://www.xbrl.org/2003/role/exampleRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 52
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-52

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-7

+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-7

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 15: http://www.xbrl.org/2003/role/exampleRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 52
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-52

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-7

+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-28

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482765/220-10-50-6

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-8

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-9

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 13: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 830
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480167/946-830-55-10

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483581/946-220-45-7

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(9))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(1)(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 20: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-30

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 32: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-31

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483499/205-20-50-7

Reference 35: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1A

Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1B

Reference 38: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 39: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

+ Details

- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 6.B)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-5

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-30

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-10

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-31

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-11

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

+ Details

REVENUE Variable Consideration (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue, Methods, Inputs, and Assumptions Used [Abstract]
Revenue, Variable Consideration Constraint Increase (Decrease)	$ 118.5	$ 108.5	$ 215.0	$ 203.6
Prior Period Adjustment [Abstract]
Prior Period Reclassification Adjustment		$ 6.2		$ (13.9)

SCHEDULE OF SHARE-BASED PAYMENT AWARD, VALUATION ASSUMPTIONS (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2023 Rate	Jun. 30, 2023 Rate	Jun. 30, 2022 Rate
Share-Based Payment Arrangement [Abstract]
WESCO expected volatility	51.00%	50.00%	43.00%
Risk free interest rate	4.00%	4.10%	1.90%
Expected life (in years)	5 years	5 years	7 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.89%	0.88%

COMMITMENTS AND CONTINGENCIES	6 Months Ended
COMMITMENTS AND CONTINGENCIES	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	From time to time, a number of lawsuits and claims have been or may be asserted against the Company relating to the conduct of its business, including litigation relating to commercial, product and employment matters (including wage and hour). The outcome of any litigation cannot be predicted with certainty, and some lawsuits may be determined adversely to Wesco. However, management does not believe that the ultimate outcome of any such pending matters is likely to have a material adverse effect on Wesco's financial condition or liquidity, although the resolution in any fiscal period of one or more of these matters may have a material adverse effect on Wesco's results of operations for that period.

GOODWILL (Tables)

6 Months Ended

Jun. 30, 2023

Goodwill [Line Items]

Schedule of Goodwill [Table Text Block]


	Six Months Ended
	June 30, 2023
	EES		CSS		UBS		Total
	(In millions)
Beginning balance, January 1	$	825.5	$	1,208.9	$	1,206.5	$	3,240.9
Foreign currency exchange rate changes	12.3		1.1		6.1		19.5
Adjustments to goodwill for acquisitions(1)	—		6.2		—		6.2
Ending balance, June 30	$	837.8	$	1,216.2	$	1,212.6	$	3,266.6

(1) Reflects the effect on goodwill of adjustments to the assets acquired and liabilities assumed in the acquisition of Rahi Systems since their initial measurement, which is part of the CSS segment, as described in Note 4, "Acquisitions".

Schedule of Finite-Lived Intangible Assets

The components of intangible assets are as follows:


		As of
		June 30, 2023						December 31, 2022
	Life (in years)	Gross Carrying Amount (1)		Accumulated Amortization (1)		Net Carrying Amount		Gross Carrying Amount (1)		Accumulated Amortization (1)		Net Carrying Amount
Intangible assets:		(In millions)
Trademarks	Indefinite	$	793.0	$	—	$	793.0	$	792.1	$	—	$	792.1
Customer relationships	10 - 20	1,521.7		(423.8)		1,097.9		1,516.0		(377.6)		1,138.4
Distribution agreements	15 and 19	29.2		(25.2)		4.0		29.2		(24.4)		4.8
Trademarks	5 and 12	15.5		(8.4)		7.1		15.5		(7.4)		8.1
		$	2,359.4	$	(457.4)	$	1,902.0	$	2,352.8	$	(409.4)	$	1,943.4

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

The following table sets forth the remaining estimated amortization expense for intangible assets for the next five years and thereafter:


For the year ending December 31,	(In millions)
2023	$	44.6
2024	86.3
2025	83.2
2026	77.8
2027	74.9
Thereafter	742.2

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482548/350-20-55-24

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1A

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-2

+ Details

- Definition

Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482548/350-20-55-24

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-1A

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482573/350-20-50-2

+ Details

STOCK-BASED COMPENSATION (Notes)

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

Wesco’s stock-based compensation awards consist of stock options, stock-settled stock appreciation rights, restricted stock units and performance-based awards. Compensation cost for all stock-based awards is measured at fair value on the date of grant and compensation cost is recognized, net of estimated forfeitures, over the service period for awards expected to vest. The fair value of stock options and stock-settled stock appreciation rights is determined using the Black-Scholes model. The fair value of restricted stock units and performance-based awards with performance conditions is determined by the grant-date closing price of Wesco’s common stock. The forfeiture assumption is based on Wesco’s historical participant behavior that is reviewed on at least an annual basis. For stock options and stock-settled stock appreciation rights that are exercised, and for restricted stock units and performance-based awards that vest, shares are issued out of Wesco's outstanding common stock.

Stock options and stock-settled stock appreciation rights vest ratably over a three-year period and terminate on the tenth anniversary of the grant date unless terminated sooner under certain conditions. Restricted stock unit awards that were granted under the Company’s 1999 Long-Term Incentive Plan, as amended and restated, vest fully on the third anniversary of the date of grant. The special award described below vests in tranches. Restricted stock units awarded under the WESCO International, Inc. 2021 Omnibus Incentive Plan, which was adopted on May 27, 2021, vest ratably over a three-year period on each of the first, second and third anniversaries of the grant date. Vesting of performance-based awards is based on a three-year performance period, and the number of shares earned, if any, depends on the attainment of certain performance levels. Outstanding awards would vest upon the consummation of a change in control transaction with performance-based awards vesting at the target level.

On July 2, 2020, a special award of restricted stock units was granted to certain officers of the Company. These awards vested in tranches of 30% on each of the first and second anniversaries of the grant date and will vest 40% on the third anniversary of the grant date, subject to continued employment through the applicable anniversary date.

Performance-based awards are based on two equally-weighted performance measures: the three-year average growth rate of Wesco's net income attributable to common stockholders and the three-year cumulative return on net assets. These awards are accounted for as awards with performance conditions; compensation cost is recognized over the performance period based upon Wesco's determination of whether it is probable that the performance targets will be achieved.

During the three and six months ended June 30, 2023 and 2022, Wesco granted the following stock options, restricted stock units, and performance-based awards at the following weighted-average fair values:


	Three Months Ended				Six Months Ended
	June 30, 2023		June 30, 2022		June 30, 2023		June 30, 2022
Stock options granted	1,954		—		77,136		89,550
Weighted-average fair value	$	76.75	$	—	$	76.77	$	57.26

Restricted stock units granted	3,295		—		173,864		224,946
Weighted-average fair value	$	138.11	$	—	$	170.41	$	122.11

Performance-based awards granted(1)	3,074		—		211,445		83,991
Weighted-average fair value(1)	$	150.32	$	—	$	86.88	$	122.09

(1) As described further below, the six months ended June 30, 2023 includes performance-based awards granted in February 2020 for which actual achievement levels were certified in February 2023, as well as performance-based awards granted during the six months ended June 30, 2023.

The fair values of stock options, as disclosed in the table above, were estimated using the following weighted-average assumptions in the respective periods:


	Three Months Ended			Six Months Ended
	June 30, 2023		June 30, 2022	June 30, 2023		June 30, 2022
Risk free interest rate	4.0	%	n/a	4.1	%	1.9	%
Expected life (in years)	5		n/a	5		7
Expected volatility	51	%	n/a	50	%	43	%
Expected dividend yield	0.89	%	n/a	0.88	%	n/a

The risk-free interest rate is based on the U.S. Treasury Daily Yield Curve rate as of the grant date. The expected life is based on historical exercise experience, the expected volatility is based on the volatility of the Company's daily stock price over the expected life preceding the grant date of the award, and the expected dividend yield is based on the calculated yield on the Company's common stock at date of grant using the current fiscal year projected dividend distribution rate. The Company did not pay dividends to holders of its common stock during the three and six months ended June 30, 2022.

The following table sets forth a summary of stock options and related information for the six months ended June 30, 2023:


	Awards	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In years)	Aggregate Intrinsic Value (In millions)
Outstanding at December 31, 2022	87,347	$	121.55
Granted	77,136	169.99
Exercised	(1,279)	122.09
Forfeited	—	—
Outstanding at June 30, 2023	163,204	$	144.44	9.1	$	5.7
Exercisable at June 30, 2023	27,782	$	121.89	8.6	$	1.6

For the six months ended June 30, 2023, the aggregate intrinsic value of stock options exercised during such period was not material.

The following table sets forth a summary of stock-settled stock appreciation rights and related information for the six months ended June 30, 2023:


	Awards	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In years)	Aggregate Intrinsic Value (In millions)
Outstanding at December 31, 2022	1,248,115	$	62.02
Granted	—	—
Exercised	(406,625)	66.80
Forfeited	(638)	72.15
Outstanding at June 30, 2023	840,852	$	59.71	5.5	$	100.4
Exercisable at June 30, 2023	799,354	$	58.81	5.4	$	96.1

For the six months ended June 30, 2023, the aggregate intrinsic value of stock-settled stock appreciation rights exercised during such period was $37.9 million.

The following table sets forth a summary of restricted stock units and related information for the six months ended June 30, 2023:


	Awards	Weighted- Average Fair Value
Unvested at December 31, 2022	774,233	$	73.79
Granted	173,864	170.41
Vested	(336,063)	71.74
Forfeited	(15,582)	121.07
Unvested at June 30, 2023	596,452	$	101.88

The following table sets forth a summary of performance-based awards and related information for the six months ended June 30, 2023:


	Awards	Weighted- Average Fair Value
Unvested at December 31, 2022	335,329	$	75.26
Granted(1)	211,445	86.88
Vested	(289,394)	48.32
Forfeited	—	—
Unvested at June 30, 2023	257,380	$	115.09

(1) Includes 63,098 performance-based awards granted in February 2023 with a fair value of $171.96 and three-year performance period ending December 31, 2025, and 144,697 performance-based awards granted in February 2020 with a fair value of $48.32 and three-year performance period ended December 31, 2022 for which actual achievement levels were certified in February 2023. Also includes 3,074 performance-based awards granted during the three months ended June 30, 2023 with a weighted-average fair value of $150.32 and three-year performance period ending December 31, 2025.

Wesco recognized $12.2 million and $15.8 million of non-cash stock-based compensation expense for the three months ended June 30, 2023 and 2022, respectively, and $23.9 million and $24.7 million for the six months ended June 30, 2023 and 2022, respectively, which is included in selling, general and administrative expenses for such periods. As of June 30, 2023, there was $72.3 million of total unrecognized compensation expense related to non-vested stock-based compensation arrangements for all awards previously made of which approximately $22.3 million is expected to be recognized over the remainder of 2023, $31.2 million in 2024, $16.8 million in 2025 and $2.0 million in 2026.

FAIR VALUE (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative, Notional Amount	$ 132.9	$ 172.8
Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	2,876.3	2,929.5
Long-term Debt	$ 2,823.1	$ 2,881.2

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References + Details

Defined Contribution Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Postemployment Benefits [Abstract]
Defined Contribution Plan, Cost	$ 21.5	$ 14.9	$ 42.9	$ 33.0

GOODWILL (Notes)

6 Months Ended

Jun. 30, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets Disclosure

The following table sets forth the changes in the carrying value of goodwill by reportable segment for the period presented:


	Six Months Ended
	June 30, 2023
	EES		CSS		UBS		Total
	(In millions)
Beginning balance, January 1	$	825.5	$	1,208.9	$	1,206.5	$	3,240.9
Foreign currency exchange rate changes	12.3		1.1		6.1		19.5
Adjustments to goodwill for acquisitions(1)	—		6.2		—		6.2
Ending balance, June 30	$	837.8	$	1,216.2	$	1,212.6	$	3,266.6

The components of intangible assets are as follows:


		As of
		June 30, 2023						December 31, 2022
	Life (in years)	Gross Carrying Amount (1)		Accumulated Amortization (1)		Net Carrying Amount		Gross Carrying Amount (1)		Accumulated Amortization (1)		Net Carrying Amount
Intangible assets:		(In millions)
Trademarks	Indefinite	$	793.0	$	—	$	793.0	$	792.1	$	—	$	792.1
Customer relationships	10 - 20	1,521.7		(423.8)		1,097.9		1,516.0		(377.6)		1,138.4
Distribution agreements	15 and 19	29.2		(25.2)		4.0		29.2		(24.4)		4.8
Trademarks	5 and 12	15.5		(8.4)		7.1		15.5		(7.4)		8.1
		$	2,359.4	$	(457.4)	$	1,902.0	$	2,352.8	$	(409.4)	$	1,943.4

(1) Excludes the original cost and related accumulated amortization of fully-amortized intangible assets.

Amortization expense related to intangible assets totaled $22.4 million and $24.7 million for the three months ended June 30, 2023 and 2022, respectively, and $44.4 million and $50.4 million for the six months ended June 30, 2023 and 2022, respectively.

The following table sets forth the remaining estimated amortization expense for intangible assets for the next five years and thereafter:


For the year ending December 31,	(In millions)
2023	$	44.6
2024	86.3
2025	83.2
2026	77.8
2027	74.9
Thereafter	742.2

Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Segment Reporting (Details) - USD ($) $ in Millions	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Segment Reporting [Abstract]
Revenues	$ 5,745.5	$ 5,483.5	$ 11,267.4	$ 10,415.7
Operating Income (Loss)	363.8	370.7	710.2	654.7
Adjusted EBITDA	$ 442.3	444.4	863.0	808.5
Adjusted EBITDA Margin %	11.10%
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 5,745.5	5,483.5	11,267.4	10,415.7
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating Income (Loss)	363.8	370.7	710.2	654.7
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	15,162.7		15,162.7		$ 14,811.7
EES
Segment Reporting [Abstract]
Adjusted EBITDA	$ 189.0	$ 235.4	$ 372.0	$ 427.9
Adjusted EBITDA Margin %	8.60%	10.10%	8.60%	9.70%
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,200.3	$ 2,330.1	$ 4,335.4	$ 4,420.1
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	4,555.9		4,555.9		4,480.4
CSS
Segment Reporting [Abstract]
Adjusted EBITDA	$ 179.5	$ 150.0	$ 335.0	$ 273.1
Adjusted EBITDA Margin %	9.70%	9.40%	9.30%	9.00%
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 1,850.9	$ 1,602.0	$ 3,582.9	$ 3,036.2
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	5,680.6		5,680.6		5,504.0
UBS
Segment Reporting [Abstract]
Adjusted EBITDA	$ 188.6	$ 169.0	$ 376.3	$ 305.4
Adjusted EBITDA Margin %	11.10%	10.90%	11.20%	10.30%
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 1,694.3	$ 1,551.4	$ 3,349.1	$ 2,959.4
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,942.1		3,942.1		3,827.4
Corporate Segment
Segment Reporting [Abstract]
Adjusted EBITDA	(114.8)	$ (110.0)	(220.3)	$ (197.9)
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 984.1		$ 984.1		$ 999.9

REVENUE (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
REVENUE (Details) - USD ($) $ in Millions	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Deferred Revenue	$ 104.8		$ 104.8		$ 99.6
Revenue from Contract with Customer, Excluding Assessed Tax	5,745.5	$ 5,483.5	11,267.4	$ 10,415.7
Cost of goods sold	4,503.1	4,294.1	8,816.5	8,177.2
Contract with Customer, Refund Liability	41.9		41.9		$ 46.5
EES
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,200.3	2,330.1	4,335.4	4,420.1
CSS
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,850.9	1,602.0	3,582.9	3,036.2
UBS
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,694.3	1,551.4	3,349.1	2,959.4
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,272.5	4,039.9	8,363.0	7,694.1
CANADA
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	773.1	807.8	1,532.5	1,522.9
Non-US [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	699.9	635.8	1,371.9	1,198.7
Shipping and Handling [Member]
Disaggregation of Revenue [Line Items]
Cost of goods sold	$ 79.1	$ 76.5	$ 156.0	$ 144.1

ACCOUNTING POLICIES	6 Months Ended
ACCOUNTING POLICIES	Jun. 30, 2023
Accounting Policies [Abstract]
ACCOUNTING POLICIES	Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements of Wesco have been prepared in accordance with Rule 10-01 of Regulation S-X of the Securities and Exchange Commission (the “SEC”). The unaudited condensed consolidated financial information should be read in conjunction with the audited Consolidated Financial Statements and Notes thereto included in WESCO International, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2022, as filed with the SEC on February 21, 2023. The Condensed Consolidated Balance Sheet at December 31, 2022 was derived from the audited Consolidated Financial Statements as of that date, but does not include all the disclosures required by accounting principles generally accepted in the United States of America. The unaudited Condensed Consolidated Balance Sheet as of June 30, 2023, the unaudited Condensed Consolidated Statements of Income and Comprehensive Income, the unaudited Condensed Consolidated Statements of Stockholders' Equity for the three and six months ended June 30, 2023, and 2022, and the unaudited Condensed Consolidated Statements of Cash Flows for the six months ended June 30, 2023, and 2022, respectively, in the opinion of management, have been prepared on the same basis as the audited Consolidated Financial Statements and include all adjustments necessary for the fair statement of the results of the interim periods presented herein. All adjustments reflected in the unaudited condensed consolidated financial information are of a normal recurring nature unless indicated. The results for the interim periods presented herein are not necessarily indicative of the results to be expected for the full year. Recently Adopted and Recently Issued Accounting Standards In September 2022, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2022-04, Supplier Finance Programs (Subtopic 405-50): Disclosure of Supplier Finance Program Obligations, which requires that a buyer in a supplier finance program disclose sufficient information about the program to allow a user of financial statements to understand the program's nature, activity during the period, changes from period to period, and potential magnitude. The amendments in this ASU are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, except for the amendment on rollforward information, which is effective for fiscal years beginning after December 15, 2023. The Company adopted this ASU in the first quarter of 2023, except for the amendment on rollforward information, which the Company will begin disclosing in its Annual Report on Form 10-K for the fiscal year ending December 31, 2023. The adoption of this ASU resulted in additional disclosure of the Company's supplier finance program, as described below. Other pronouncements issued by the FASB or other authoritative accounting standards groups with future effective dates are either not applicable or are not expected to be significant to Wesco’s financial position, results of operations or cash flows.
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	Recently Adopted and Recently Issued Accounting Standards
Supplier Finance Program	Supplier Finance Programs The Company has a supplier finance program that is administered by an intermediary. Under this arrangement, participating suppliers may elect to receive early payment of invoices that have been confirmed by the Company, less an interest deduction, which is paid to the supplier by a third-party finance provider. Wesco agrees to pay the stated amount of confirmed invoices in full on the original due date of the invoices, which is typically within 45 to 90 days of the invoice date, regardless of whether the supplier elects to receive early payment from the third-party finance provider. The Company does not provide assets pledged as security or other forms of guarantees to the finance provider or intermediary under this arrangement. As of June 30, 2023 and December 31, 2022, the amounts due to suppliers that participate in the Company's supplier finance program were approximately $29.4 million and $30.7 million, respectively, which are included in accounts payable in the Condensed Consolidated Balance Sheet.

- Definition

The entire disclosure for change in accounting principle. Includes, but is not limited to, nature, reason, and method of adopting amendment to accounting standards or other change in accounting principle.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iv)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (h)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 11.M.Q2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480530/250-10-S99-5

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (i)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479832/842-10-65-5

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (f)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479832/842-10-65-5

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483550/848-10-65-2

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479343/105-10-65-6

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482615/740-10-65-8

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482615/740-10-65-8

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (e)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482615/740-10-65-8

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482833/825-10-65-6

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482833/825-10-65-6

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (e)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482833/825-10-65-6

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-4

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-4

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 926
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483194/926-20-65-2

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 926
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483194/926-20-65-2

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 926
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (f)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483194/926-20-65-2

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480530/250-10-S99-6

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Topic 250
-Publisher FASB
-URI https://asc.fasb.org//250/tableOfContent

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (d)(1)
-SubTopic 20
-Topic 310
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481925/310-20-65-2

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (d)(2)
-SubTopic 20
-Topic 310
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481925/310-20-65-2

+ Details

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY Statement - USD ($) $ in Millions	Total	Common Class B [Member]	Common Stock [Member]	Series A Preferred Stock [Member]	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]	Retained Earnings [Member]	Additional Paid-in Capital [Member]	Treasury Stock, Common [Member]
Common stock		$ 0.0	$ 0.7
Common Stock, Shares, Issued		4,339,431	68,162,297
Additional capital	$ 1,969.3
Retained Earnings (Accumulated Deficit)	3,004.7
Treasury Stock, Value	(956.2)
Stockholders' Equity Attributable to Noncontrolling Interest	(6.3)
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (236.0)
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding				$ 0.0
Preferred stock, shares issued (in shares)				21,612
Treasury Stock, Common, Shares	22,026,922
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 3,776.2
Stock Issued, Value, Stock Options Exercised, Net of Tax Benefit (Expense)	(0.6)		$ 0.0						$ 0.6
APIC, Share-based Payment Arrangement, Recognition and Exercise	0.0
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	8.9
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(15.9)		$ 0.0				$ 8.1	$ 7.8
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period			365,833						858
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation			(129,869)
Net Income (Loss) Attributable to Parent	181.2
Dividends, Preferred Stock	(14.4)
Net Income (Loss) Attributable to Noncontrolling Interest	0.4					$ 0.4
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	31.6				$ 31.6
Net Income (Loss) Attributable to Parent	401.9
Dividends, Preferred Stock	(28.7)
Net Income (Loss) Attributable to Noncontrolling Interest	0.8
Common stock		$ 0.0	$ 0.7
Common Stock, Shares, Issued		4,339,431	68,398,261
Additional capital	1,970.4
Retained Earnings (Accumulated Deficit)	3,163.4
Treasury Stock, Value	(956.8)
Stockholders' Equity Attributable to Noncontrolling Interest	(5.9)
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (204.4)
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding				$ 0.0
Preferred stock, shares issued (in shares)				21,612
Treasury Stock, Common, Shares	22,027,780
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 3,967.4
Stock Issued, Value, Stock Options Exercised, Net of Tax Benefit (Expense)	(0.3)		$ 0.0						$ 0.3
APIC, Share-based Payment Arrangement, Recognition and Exercise	0.0
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	15.8
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	0.0		$ 0.0				0.0	0.0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period			11,648						2,301
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation			(908)
Net Income (Loss) Attributable to Parent	220.7
Dividends, Preferred Stock	(14.4)
Stockholders' Equity, Other							1.2	(0.2)
Net Income (Loss) Attributable to Noncontrolling Interest	0.4					0.4
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(78.4)				(79.4)
Common stock		$ 0.0	$ 0.7
Common Stock, Shares, Issued		4,339,431	68,409,001
Additional capital	1,986.0
Retained Earnings (Accumulated Deficit)	3,370.9
Stockholders' Equity Attributable to Noncontrolling Interest	(5.5)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(283.8)
Treasury stock, at cost; 22,211,365 and 22,115,653 shares in 2023 and 2022, respectively	$ (957.1)
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding				$ 0.0
Preferred stock, shares issued (in shares)				21,612
Treasury Stock, Common, Shares	22,030,081
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 4,111.2
Common stock		$ 0.0	$ 0.7
Common Stock, Shares, Issued		4,339,431	68,535,704
Additional capital	2,005.4
Retained Earnings (Accumulated Deficit)	3,795.0
Treasury Stock, Value	(969.1)
Stockholders' Equity Attributable to Noncontrolling Interest	(4.7)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(377.7)
Treasury stock, at cost; 22,211,365 and 22,115,653 shares in 2023 and 2022, respectively	$ (969.1)
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding				$ 0.0
Preferred stock, shares issued (in shares)				21,612
Treasury Stock, Common, Shares	22,115,653
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 4,449.6
Stock Issued, Value, Stock Options Exercised, Net of Tax Benefit (Expense)	(12.6)		$ 0.0						$ 12.9
APIC, Share-based Payment Arrangement, Recognition and Exercise	0.3
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	11.7
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(38.7)		$ 0.0				24.5	14.2
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period			811,309						79,817
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation			(236,953)
Net Income (Loss) Attributable to Parent	197.1
Dividends, Preferred Stock	(14.4)
Stockholders' Equity, Other							(1.0)	0.1
Net Income (Loss) Attributable to Noncontrolling Interest	0.1					0.1
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	16.1				17.0
Dividends, Common Stock	(19.2)
Net Income (Loss) Attributable to Parent	390.2
Net Income (Loss) Attributable to Noncontrolling Interest	(0.6)
Common stock		$ 0.0	$ 0.7
Common Stock, Shares, Issued		4,339,431	69,110,060
Additional capital	2,003.3
Retained Earnings (Accumulated Deficit)	3,933.0
Treasury Stock, Value	(982.0)
Stockholders' Equity Attributable to Noncontrolling Interest	(4.6)
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (360.7)
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding				$ 0.0
Preferred stock, shares issued (in shares)				21,612
Treasury Stock, Common, Shares	22,195,470
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 4,589.7
Stock Issued, Value, Stock Options Exercised, Net of Tax Benefit (Expense)	(2.4)		$ 0.0						$ 2.5
APIC, Share-based Payment Arrangement, Recognition and Exercise	0.1
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	12.2
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(0.2)		$ 0.0				0.1	$ 0.1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period			56,044						15,895
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation			(1,111)
Net Income (Loss) Attributable to Parent	193.1
Dividends, Preferred Stock	(14.4)
Stockholders' Equity, Other							$ 1.0
Net Income (Loss) Attributable to Noncontrolling Interest	(0.7)					$ (0.7)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	42.2				$ 41.2
Dividends, Common Stock	(19.2)
Common stock		$ 0.0	$ 0.7
Common Stock, Shares, Issued		4,339,431	69,164,993
Additional capital	2,015.5
Retained Earnings (Accumulated Deficit)	4,093.4
Stockholders' Equity Attributable to Noncontrolling Interest	(5.3)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(319.5)
Treasury stock, at cost; 22,211,365 and 22,115,653 shares in 2023 and 2022, respectively	$ (984.5)
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding				$ 0.0
Preferred stock, shares issued (in shares)				21,612
Treasury Stock, Common, Shares	22,211,365
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 4,800.3

INCOME TAXES Income Tax Rates (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, Percent	27.20%	26.50%	22.90%	22.60%
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent	30.00%	10.00%	440.00%	370.00%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Amount	$ 0.9	$ 0.3	$ 22.1	$ 6.1

Segment Reporting

6 Months Ended

Jun. 30, 2023

Segment Reporting [Abstract]

Segment Reporting Disclosure

13. BUSINESS SEGMENTS

The Company has operating segments comprising three strategic business units consisting of EES, CSS and UBS. These operating segments are equivalent to the Company's reportable segments. The Company's chief operating decision maker evaluates the performance of its operating segments based on net sales, adjusted earnings before interest, taxes, depreciation and amortization (“EBITDA”), and adjusted EBITDA margin percentage.

The Company incurs corporate costs primarily related to treasury, tax, information technology, legal and other centralized functions. The Company also has various corporate assets. Segment assets may not include jointly used assets, but segment results include depreciation expense or other allocations related to those assets. Interest expense and other non-operating items are either not allocated to the segments or reviewed on a segment basis. Corporate expenses and assets not directly identifiable with a reportable segment are reported in the tables below to reconcile the reportable segments to the consolidated financial statements.

The following tables set forth financial information by reportable segment for the periods presented:


(In millions)	Three Months Ended June 30, 2023
	EES		CSS		UBS		Total
Net sales	$	2,200.3	$	1,850.9	$	1,694.3	$	5,745.5

	Three Months Ended June 30, 2022
(In millions)	EES		CSS		UBS		Total
Net sales	$	2,330.1	$	1,602.0	$	1,551.4	$	5,483.5


(In millions)	Six Months Ended June 30, 2023
	EES		CSS		UBS		Total
Net sales	$	4,335.4	$	3,582.9	$	3,349.1	$	11,267.4

	Six Months Ended June 30, 2022
(In millions)	EES		CSS		UBS		Total
Net sales	$	4,420.1	$	3,036.2	$	2,959.4	$	10,415.7


(In millions)	Three Months Ended June 30, 2023
	EES			CSS			UBS
Adjusted EBITDA	$	189.0		$	179.5		$	188.6
Adjusted EBITDA Margin %	8.6		%	9.7		%	11.1		%

	Three Months Ended June 30, 2022
(In millions)	EES			CSS			UBS
Adjusted EBITDA	$	235.4		$	150.0		$	169.0
Adjusted EBITDA Margin %	10.1		%	9.4		%	10.9		%


(In millions)	Six Months Ended June 30, 2023
	EES			CSS			UBS
Adjusted EBITDA	$	372.0		$	335.0		$	376.3
Adjusted EBITDA Margin %	8.6		%	9.3		%	11.2		%

	Six Months Ended June 30, 2022
(In millions)	EES			CSS			UBS
Adjusted EBITDA	$	427.9		$	273.1		$	305.4
Adjusted EBITDA Margin %	9.7		%	9.0		%	10.3		%

The following table sets forth total assets by reportable segment for the periods presented:


	As of
	June 30, 2023
(In millions)	EES		CSS		UBS		Corporate(1)		Total
Total assets	$	4,555.9	$	5,680.6	$	3,942.1	$	984.1	$	15,162.7

	As of
	December 31, 2022
(In millions)	EES		CSS		UBS		Corporate(1)		Total
Total assets	$	4,480.4	$	5,504.0	$	3,827.4	$	999.9	$	14,811.7

(1) Total assets for Corporate primarily consist of cash and cash equivalents, deferred income taxes, property, buildings and equipment, capitalized cloud computing arrangement costs, operating lease assets, and pension assets.

The following tables reconcile net income attributable to common stockholders to adjusted EBITDA and adjusted EBITDA margin % by segment, which are non-GAAP financial measures, for the periods presented:


	Three Months Ended June 30, 2023
(In millions)	EES			CSS			UBS			Corporate		Total
Net income attributable to common stockholders	$	167.0		$	132.2		$	183.1		$	(303.6)	$	178.7
Net (loss) income attributable to noncontrolling interests	(0.7)			0.1			—			(0.1)		(0.7)
Preferred stock dividends	—			—			—			14.4		14.4
Provision for income taxes(1)	—			—			—			71.8		71.8
Interest expense, net(1)	—			—			—			98.8		98.8
Depreciation and amortization	11.5			17.9			6.4			11.1		46.9
Other expense (income), net	9.8			27.7			(1.7)			(35.0)		0.8
Stock-based compensation expense(2)	1.4			1.6			0.8			7.1		10.9
Merger-related and integration costs(3)	—			—			—			10.9		10.9
Restructuring costs(4)	—			—			—			9.8		9.8
Adjusted EBITDA	$	189.0		$	179.5		$	188.6		$	(114.8)	$	442.3
Adjusted EBITDA margin %	8.6		%	9.7		%	11.1		%
(1) The reportable segments do not incur income taxes and interest expense as these costs are centrally controlled through the Corporate tax and treasury functions.
(2) Stock-based compensation expense in the calculation of adjusted EBITDA for the three months ended June 30, 2023 excludes $1.3 million that is included in merger-related and integration costs.
(3) Merger-related and integration costs include integration and professional fees associated with the integration of Wesco and Anixter, including digital transformation costs, as well as advisory, legal, and separation costs associated with the merger between the two companies.
(4) Restructuring costs include severance costs incurred pursuant to an ongoing restructuring plan.


	Three Months Ended June 30, 2022
(In millions)	EES			CSS			UBS			Corporate		Total
Net income attributable to common stockholders	$	222.8		$	130.6		$	161.8		$	(308.9)	$	206.3
Net income attributable to noncontrolling interests	0.1			—			—			0.3		0.4
Preferred stock dividends	—			—			—			14.4		14.4
Provision for income taxes(1)	—			—			—			79.9		79.9
Interest expense, net(1)	—			—			—			68.5		68.5
Depreciation and amortization	11.2			17.9			5.7			11.0		45.8
Other (income) expense, net	(1.4)			0.1			0.6			1.9		1.2
Stock-based compensation expense(2)	2.7			1.4			0.9			9.5		14.5
Merger-related and integration costs(3)	—			—			—			13.4		13.4
Adjusted EBITDA	$	235.4		$	150.0		$	169.0		$	(110.0)	$	444.4
Adjusted EBITDA margin %	10.1		%	9.4		%	10.9		%
(1) The reportable segments do not incur income taxes and interest expense as these costs are centrally controlled through the Corporate tax and treasury functions.
(2) Stock-based compensation expense in the calculation of adjusted EBITDA for the three months ended June 30, 2022 excludes $1.4 million that is included in merger-related and integration costs.
(3) Merger-related and integration costs include integration and professional fees associated with the integration of Wesco and Anixter, including digital transformation costs, as well as advisory, legal, and separation costs associated with the merger between the two companies.


	Six Months Ended June 30, 2023
(In millions)	EES			CSS			UBS			Corporate		Total
Net income attributable to common stockholders	$	338.3		$	267.6		$	363.4		$	(607.8)	$	361.5
Net (loss) income attributable to noncontrolling interests	(0.8)			0.3			—			(0.1)		(0.6)
Preferred stock dividends	—			—			—			28.7		28.7
Provision for income taxes(1)	—			—			—			115.9		115.9
Interest expense, net(1)	—			—			—			193.8		193.8
Depreciation and amortization	21.4			35.9			12.4			21.6		91.3
Other expense (income), net	10.3			28.5			(1.1)			(26.8)		10.9
Stock-based compensation expense(2)	2.8			2.7			1.6			14.2		21.3
Merger-related and integration costs(3)	—			—			—			30.4		30.4
Restructuring costs(4)	—			—			—			9.8		9.8
Adjusted EBITDA	$	372.0		$	335.0		$	376.3		$	(220.3)	$	863.0
Adjusted EBITDA margin %	8.6		%	9.3		%	11.2		%
(1) The reportable segments do not incur income taxes and interest expense as these costs are centrally controlled through the Corporate tax and treasury functions.
(2) Stock-based compensation expense in the calculation of adjusted EBITDA for the six months ended June 30, 2023 excludes $2.6 million that is included in merger-related and integration costs.
(3) Merger-related and integration costs include integration and professional fees associated with the integration of Wesco and Anixter, including digital transformation costs, as well as advisory, legal, and separation costs associated with the merger between the two companies.
(4) Restructuring costs include severance costs incurred pursuant to an ongoing restructuring plan.


	Six Months Ended June 30, 2022
(In millions)	EES			CSS			UBS			Corporate		Total
Net income attributable to common stockholders	$	401.5		$	234.3		$	291.8		$	(554.4)	$	373.2
Net income attributable to noncontrolling interests	0.4			—			—			0.4		0.8
Preferred stock dividends	—			—			—			28.7		28.7
Provision for income taxes(1)	—			—			—			117.6		117.6
Interest expense, net(1)	—			—			—			132.1		132.1
Depreciation and amortization	23.2			36.0			11.5			22.1		92.8
Other (income) expense, net	(1.6)			0.5			0.6			2.8		2.3
Stock-based compensation expense(2)	4.4			2.3			1.5			13.8		22.0
Merger-related and integration costs(3)	—			—			—			39.0		39.0
Adjusted EBITDA	$	427.9		$	273.1		$	305.4		$	(197.9)	$	808.5
Adjusted EBITDA margin %	9.7		%	9.0		%	10.3		%
(1) The reportable segments do not incur income taxes and interest expense as these costs are centrally controlled through the Corporate tax and treasury functions.
(2) Stock-based compensation expense in the calculation of adjusted EBITDA for the six months ended June 30, 2022 excludes $2.7 million that is included in merger-related and integration costs.
(3) Merger-related and integration costs include integration and professional fees associated with the integration of Wesco and Anixter, including digital transformation costs, as well as advisory, legal, and separation costs associated with the merger between the two companies.

Note: Adjusted EBITDA and Adjusted EBITDA margin % are non-GAAP financial measures that provide indicators of the Company's performance and its ability to meet debt service requirements. Adjusted EBITDA is defined as earnings before interest, taxes, depreciation and amortization before other non-operating expenses (income), non-cash stock-based compensation expense, merger-related and integration costs, and restructuring costs. Adjusted EBITDA margin % is calculated by dividing Adjusted EBITDA by net sales.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-31

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-42

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 40
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-40

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//280/tableOfContent

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 26
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-26

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 34
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-34

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-41

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-21

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-21

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

+ Details

Business Combinations and Asset Acquisitions (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023
Asset Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Reasons		The estimated fair values of assets acquired and liabilities assumed are based on preliminary calculations and valuations using estimates and assumptions at the time of acquisition. As the Company obtains additional information during the measurement period (not to exceed one year from the acquisition date), estimates and assumptions for the preliminary purchase consideration allocations may change materially.
Goodwill, Purchase Accounting Adjustments		$ 6.2
Rahi Systems
Asset Acquisition [Line Items]
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	$ 150.3	$ 286.6
Business Acquisition, Description of Acquired Entity		Headquartered in Fremont, California, Rahi Systems is a leading provider of global hyperscale data center solutions with over 900 employees in 25 countries.
Business Combination, Reason for Business Combination		Rahi's expertise with complex information technology projects and global presence strengthen Wesco's data center solution offerings.
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory		$ 21.8
BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAccountsPayable		28.0
Goodwill, Purchase Accounting Adjustments		$ 6.2

STOCK-BASED COMPENSATION (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended			12 Months Ended
STOCK-BASED COMPENSATION (Details) - USD ($) $ in Millions	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2023	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2026	Dec. 31, 2025	Dec. 31, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 12.2	$ 15.8		$ 23.9	$ 24.7
Total unrecognized compensation cost	$ 72.3			$ 72.3
Forecast [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 22.3			$ 2.0	$ 16.8	$ 31.2

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 1D
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480483/718-10-35-1D

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480483/718-10-35-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(01)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(02)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(02)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iv)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(v)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

STOCK-BASED COMPENSATION (Tables)

6 Months Ended

Jun. 30, 2023

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]


	Three Months Ended				Six Months Ended
	June 30, 2023		June 30, 2022		June 30, 2023		June 30, 2022
Stock options granted	1,954		—		77,136		89,550
Weighted-average fair value	$	76.75	$	—	$	76.77	$	57.26

Restricted stock units granted	3,295		—		173,864		224,946
Weighted-average fair value	$	138.11	$	—	$	170.41	$	122.11

Performance-based awards granted(1)	3,074		—		211,445		83,991
Weighted-average fair value(1)	$	150.32	$	—	$	86.88	$	122.09

Share-based Payment Arrangement, Option and Stock Appreciation Rights, Activity [Table Text Block]

The following table sets forth a summary of stock-settled stock appreciation rights and related information for the six months ended June 30, 2023:


	Awards	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In years)	Aggregate Intrinsic Value (In millions)
Outstanding at December 31, 2022	1,248,115	$	62.02
Granted	—	—
Exercised	(406,625)	66.80
Forfeited	(638)	72.15
Outstanding at June 30, 2023	840,852	$	59.71	5.5	$	100.4
Exercisable at June 30, 2023	799,354	$	58.81	5.4	$	96.1

For the six months ended June 30, 2023, the aggregate intrinsic value of stock-settled stock appreciation rights exercised during such period was $37.9 million.

Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

The following table sets forth a summary of restricted stock units and related information for the six months ended June 30, 2023:


	Awards	Weighted- Average Fair Value
Unvested at December 31, 2022	774,233	$	73.79
Granted	173,864	170.41
Vested	(336,063)	71.74
Forfeited	(15,582)	121.07
Unvested at June 30, 2023	596,452	$	101.88

Schedule of Nonvested Performance-based Units Activity [Table Text Block]

The following table sets forth a summary of performance-based awards and related information for the six months ended June 30, 2023:


	Awards	Weighted- Average Fair Value
Unvested at December 31, 2022	335,329	$	75.26
Granted(1)	211,445	86.88
Vested	(289,394)	48.32
Forfeited	—	—
Unvested at June 30, 2023	257,380	$	115.09

Share-Based Payment Arrangement, Option, Activity

The following table sets forth a summary of stock options and related information for the six months ended June 30, 2023:


	Awards	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In years)	Aggregate Intrinsic Value (In millions)
Outstanding at December 31, 2022	87,347	$	121.55
Granted	77,136	169.99
Exercised	(1,279)	122.09
Forfeited	—	—
Outstanding at June 30, 2023	163,204	$	144.44	9.1	$	5.7
Exercisable at June 30, 2023	27,782	$	121.89	8.6	$	1.6

For the six months ended June 30, 2023, the aggregate intrinsic value of stock options exercised during such period was not material.

Stock Appreciation Rights (SARs) [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The fair values of stock options, as disclosed in the table above, were estimated using the following weighted-average assumptions in the respective periods:


	Three Months Ended			Six Months Ended
	June 30, 2023		June 30, 2022	June 30, 2023		June 30, 2022
Risk free interest rate	4.0	%	n/a	4.1	%	1.9	%
Expected life (in years)	5		n/a	5		7
Expected volatility	51	%	n/a	50	%	43	%
Expected dividend yield	0.89	%	n/a	0.88	%	n/a

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

EARNINGS PER SHARE

6 Months Ended

Jun. 30, 2023

Earnings Per Share [Abstract]

EARNINGS PER SHARE

Basic earnings per share is computed by dividing net income attributable to common stockholders by the weighted-average number of common shares outstanding during the periods. Diluted earnings per share is computed by dividing net income attributable to common stockholders by the weighted-average common shares and common share equivalents outstanding during the periods. The dilutive effect of common share equivalents is considered in the diluted earnings per share computation using the treasury stock method, which includes consideration of equity awards.

The following table sets forth the computation of basic and diluted earnings per share for the periods presented:


	Three Months Ended				Six Months Ended
	June 30				June 30
(In millions, except per share data)	2023		2022(1)		2023		2022(1)
Net income attributable to WESCO International, Inc.	$	193.1	$	220.7	$	390.2	$	401.9
Less: Preferred stock dividends	14.4		14.4		28.7		28.7
Net income attributable to common stockholders	$	178.7	$	206.3	$	361.5	$	373.2
Weighted-average common shares outstanding used in computing basic earnings per share	51.3		50.7		51.1		50.7
Common shares issuable upon exercise of dilutive equity awards	1.1		1.5		1.3		1.6
Weighted-average common shares outstanding and common share equivalents used in computing diluted earnings per share	52.4		52.2		52.4		52.2
Earnings per share attributable to common stockholders
Basic	$	3.48	$	4.07	$	7.07	$	7.37
Diluted	$	3.41	$	3.95	$	6.90	$	7.15

(1) Basic and diluted earnings per share for the three and six months ended June 30, 2022 were previously calculated and reported based on amounts as presented in thousands. As such, certain prior year amounts may not foot or recalculate based on the amounts as presented in millions in the current year presentation.

The computation of diluted earnings per share attributable to common stockholders excludes stock-based awards that would have had an antidilutive effect on earnings per share. For the three and six months ended June 30, 2023, there were approximately 0.4 million antidilutive shares.

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Gross Profit [Abstract]
Revenues	$ 5,745.5	$ 5,483.5	$ 11,267.4	$ 10,415.7
Cost of goods sold	4,503.1	4,294.1	8,816.5	8,177.2
Operating Expenses [Abstract]
Selling, general and administrative expense	831.7	772.9	1,649.4	1,491.0
Depreciation and amortization	46.9	45.8	91.3	92.8
Income from operations	363.8	370.7	710.2	654.7
Interest Income (Expense), Nonoperating, Net	98.8	68.5	193.8	132.1
Other Nonoperating Income (Expense)	0.8	1.2	10.9	2.3
Income before income taxes	264.2	301.0	505.5	520.3
Provision for income taxes	71.8	79.9	115.9	117.6
Net income	192.4	221.1	389.6	402.7
Net (loss) income attributable to noncontrolling interest	(0.7)	0.4	(0.6)	0.8
Net income attributable to WESCO International, Inc.	193.1	220.7	390.2	401.9
Preferred Stock Dividends, Income Statement Impact	14.4	14.4	28.7	28.7
Net Income (Loss) Available to Common Stockholders, Basic	178.7	206.3	361.5	373.2
Comprehensive Income:
Foreign currency translation adjustment	41.2	(79.4)	58.2	(47.7)
Comprehensive income attributable to WESCO International, Inc.	$ 219.9	$ 126.9	$ 419.7	$ 325.5
Basic (in dollars per share)	$ 3.48	$ 4.07	$ 7.07	$ 7.37
Diluted (in dollars per share)	$ 3.41	$ 3.95	$ 6.90	$ 7.15

Summary of Non-Qualified Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	840,852		840,852		1,248,115
Granted (in shares)			0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercised			(406,625)
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures			(638)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number	799,354		799,354
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 59.71		$ 59.71		$ 62.02
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price			0
Weighted Average Exercise Price, Exercises in Period (in dollars per share)			66.80
Weighted Average Exercise Price, Forfeitures in Period (in dollars per share)			72.15
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 58.81		$ 58.81
Weighted Average Remaining Contractual Term, Outstanding (in years)			5 years 6 months
Aggregate Intrinsic Value, Outstanding	$ 100.4		$ 100.4
Weighted Average Remaining Contractual Term, Exercisable (in years)			5 years 4 months 24 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 96.1		$ 96.1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value			$ 37.9
Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	163,204		163,204		87,347
Granted (in shares)	1,954	0	77,136	89,550
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercised			(1,279)
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures			0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number	27,782		27,782
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 144.44		$ 144.44		$ 121.55
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price			169.99
Weighted Average Exercise Price, Exercises in Period (in dollars per share)			122.09
Weighted Average Exercise Price, Forfeitures in Period (in dollars per share)			0
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 121.89		$ 121.89
Weighted Average Remaining Contractual Term, Outstanding (in years)			9 years 1 month 6 days
Aggregate Intrinsic Value, Outstanding	$ 5.7		$ 5.7
Weighted Average Remaining Contractual Term, Exercisable (in years)			8 years 7 months 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 1.6		$ 1.6

EARNINGS PER SHARE (Tables)

6 Months Ended

Jun. 30, 2023

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The following table sets forth the computation of basic and diluted earnings per share for the periods presented:


	Three Months Ended				Six Months Ended
	June 30				June 30
(In millions, except per share data)	2023		2022(1)		2023		2022(1)
Net income attributable to WESCO International, Inc.	$	193.1	$	220.7	$	390.2	$	401.9
Less: Preferred stock dividends	14.4		14.4		28.7		28.7
Net income attributable to common stockholders	$	178.7	$	206.3	$	361.5	$	373.2
Weighted-average common shares outstanding used in computing basic earnings per share	51.3		50.7		51.1		50.7
Common shares issuable upon exercise of dilutive equity awards	1.1		1.5		1.3		1.6
Weighted-average common shares outstanding and common share equivalents used in computing diluted earnings per share	52.4		52.2		52.4		52.2
Earnings per share attributable to common stockholders
Basic	$	3.48	$	4.07	$	7.07	$	7.37
Diluted	$	3.41	$	3.95	$	6.90	$	7.15

Defined Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Defined Benefit Plans (Details) - USD ($) $ in Millions	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1.2	$ 2.1	$ 2.4	$ 4.3
Interest cost	3.5	4.4	8.9	8.8
Expected return on plan assets	(3.6)	(7.7)	(9.0)	(15.5)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(0.3)	(0.2)	(0.6)	(0.4)
Net periodic benefit cost	0.8	(1.4)	1.7	(2.8)
Defined Benefit Plan, Service Cost	1.2	2.1	2.4	4.3
Defined Benefit Plan, Plan Assets, Contributions by Employer	4.3		6.7
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.0	0.0	0.0	0.0
Interest cost	0.6	2.1	3.2	4.2
Expected return on plan assets	(0.6)	(3.5)	(3.0)	(7.0)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	0.0	0.0	0.0	0.0
Net periodic benefit cost	0.0	(1.4)	0.2	(2.8)
Defined Benefit Plan, Service Cost	0.0	0.0	0.0	0.0
Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	1.2	2.1	2.4	4.3
Interest cost	2.9	2.3	5.7	4.6
Expected return on plan assets	(3.0)	(4.2)	(6.0)	(8.5)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(0.3)	(0.2)	(0.6)	(0.4)
Net periodic benefit cost	0.8	0.0	1.5	0.0
Defined Benefit Plan, Service Cost	1.2	2.1	2.4	4.3
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	7.0		7.0
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Nonoperating Gains (Losses)	$ (0.5)	$ (3.5)	$ (0.7)	$ (7.1)

SUMMARY OF RESTRICTED STOCK UNITS (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance-based awards outstanding (in shares)	596,452		596,452		774,233
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 101.88		$ 101.88		$ 73.79
Granted (in shares)	3,295	0	173,864	224,946
Granted, Weighted Average Fair Value (in dollars per share)	$ 138.11	$ 0	$ 170.41	$ 122.11
Vested (in shares)			(336,063)
Vested in Period, Weighted Average Fair Value (in dollars per share)			$ 71.74
Forfeited (in shares)			(15,582)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value			$ 121.07

SUMMARY OF PERFORMANCE-BASED AWARDS (Details) - Performance Shares [Member] - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested (in shares)	257,380		257,380		335,329
Granted (in shares)	3,074	0	211,445	83,991
Vested (in shares)			(289,394)
Forfeited (in shares)			0
Unvested, Weighted Average Fair Value (in dollars per share)	$ 115.09		$ 115.09		$ 75.26
Granted, Weighted Average Fair Value (in dollars per share)	$ 150.32	$ 0	86.88	$ 122.09
Forfeited in Period, Weighted Average Fair Value (in dollars per share)			$ 0

REVENUE Deferred Revenue (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
REVENUE Deferred Revenue (Details) - USD ($) $ in Millions	Jun. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Deferred Revenue	$ 104.8	$ 104.8	$ 99.6
Contract with Customer, Asset, before Allowance for Credit Loss	40.7	40.7	$ 27.5
Deferred Revenue, Revenue Recognized	$ 21.0	$ 42.0

Segment Reporting (Tables)

6 Months Ended

Jun. 30, 2023

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

The following tables set forth financial information by reportable segment for the periods presented:


(In millions)	Three Months Ended June 30, 2023
	EES		CSS		UBS		Total
Net sales	$	2,200.3	$	1,850.9	$	1,694.3	$	5,745.5

	Three Months Ended June 30, 2022
(In millions)	EES		CSS		UBS		Total
Net sales	$	2,330.1	$	1,602.0	$	1,551.4	$	5,483.5


(In millions)	Six Months Ended June 30, 2023
	EES		CSS		UBS		Total
Net sales	$	4,335.4	$	3,582.9	$	3,349.1	$	11,267.4

	Six Months Ended June 30, 2022
(In millions)	EES		CSS		UBS		Total
Net sales	$	4,420.1	$	3,036.2	$	2,959.4	$	10,415.7


(In millions)	Three Months Ended June 30, 2023
	EES			CSS			UBS
Adjusted EBITDA	$	189.0		$	179.5		$	188.6
Adjusted EBITDA Margin %	8.6		%	9.7		%	11.1		%

	Three Months Ended June 30, 2022
(In millions)	EES			CSS			UBS
Adjusted EBITDA	$	235.4		$	150.0		$	169.0
Adjusted EBITDA Margin %	10.1		%	9.4		%	10.9		%


(In millions)	Six Months Ended June 30, 2023
	EES			CSS			UBS
Adjusted EBITDA	$	372.0		$	335.0		$	376.3
Adjusted EBITDA Margin %	8.6		%	9.3		%	11.2		%

	Six Months Ended June 30, 2022
(In millions)	EES			CSS			UBS
Adjusted EBITDA	$	427.9		$	273.1		$	305.4
Adjusted EBITDA Margin %	9.7		%	9.0		%	10.3		%

The following table sets forth total assets by reportable segment for the periods presented:


	As of
	June 30, 2023
(In millions)	EES		CSS		UBS		Corporate(1)		Total
Total assets	$	4,555.9	$	5,680.6	$	3,942.1	$	984.1	$	15,162.7

	As of
	December 31, 2022
(In millions)	EES		CSS		UBS		Corporate(1)		Total
Total assets	$	4,480.4	$	5,504.0	$	3,827.4	$	999.9	$	14,811.7


	Three Months Ended June 30, 2023
(In millions)	EES			CSS			UBS			Corporate		Total
Net income attributable to common stockholders	$	167.0		$	132.2		$	183.1		$	(303.6)	$	178.7
Net (loss) income attributable to noncontrolling interests	(0.7)			0.1			—			(0.1)		(0.7)
Preferred stock dividends	—			—			—			14.4		14.4
Provision for income taxes(1)	—			—			—			71.8		71.8
Interest expense, net(1)	—			—			—			98.8		98.8
Depreciation and amortization	11.5			17.9			6.4			11.1		46.9
Other expense (income), net	9.8			27.7			(1.7)			(35.0)		0.8
Stock-based compensation expense(2)	1.4			1.6			0.8			7.1		10.9
Merger-related and integration costs(3)	—			—			—			10.9		10.9
Restructuring costs(4)	—			—			—			9.8		9.8
Adjusted EBITDA	$	189.0		$	179.5		$	188.6		$	(114.8)	$	442.3
Adjusted EBITDA margin %	8.6		%	9.7		%	11.1		%
(1) The reportable segments do not incur income taxes and interest expense as these costs are centrally controlled through the Corporate tax and treasury functions.
(2) Stock-based compensation expense in the calculation of adjusted EBITDA for the three months ended June 30, 2023 excludes $1.3 million that is included in merger-related and integration costs.
(3) Merger-related and integration costs include integration and professional fees associated with the integration of Wesco and Anixter, including digital transformation costs, as well as advisory, legal, and separation costs associated with the merger between the two companies.
(4) Restructuring costs include severance costs incurred pursuant to an ongoing restructuring plan.


	Three Months Ended June 30, 2022
(In millions)	EES			CSS			UBS			Corporate		Total
Net income attributable to common stockholders	$	222.8		$	130.6		$	161.8		$	(308.9)	$	206.3
Net income attributable to noncontrolling interests	0.1			—			—			0.3		0.4
Preferred stock dividends	—			—			—			14.4		14.4
Provision for income taxes(1)	—			—			—			79.9		79.9
Interest expense, net(1)	—			—			—			68.5		68.5
Depreciation and amortization	11.2			17.9			5.7			11.0		45.8
Other (income) expense, net	(1.4)			0.1			0.6			1.9		1.2
Stock-based compensation expense(2)	2.7			1.4			0.9			9.5		14.5
Merger-related and integration costs(3)	—			—			—			13.4		13.4
Adjusted EBITDA	$	235.4		$	150.0		$	169.0		$	(110.0)	$	444.4
Adjusted EBITDA margin %	10.1		%	9.4		%	10.9		%
(1) The reportable segments do not incur income taxes and interest expense as these costs are centrally controlled through the Corporate tax and treasury functions.
(2) Stock-based compensation expense in the calculation of adjusted EBITDA for the three months ended June 30, 2022 excludes $1.4 million that is included in merger-related and integration costs.
(3) Merger-related and integration costs include integration and professional fees associated with the integration of Wesco and Anixter, including digital transformation costs, as well as advisory, legal, and separation costs associated with the merger between the two companies.


	Six Months Ended June 30, 2023
(In millions)	EES			CSS			UBS			Corporate		Total
Net income attributable to common stockholders	$	338.3		$	267.6		$	363.4		$	(607.8)	$	361.5
Net (loss) income attributable to noncontrolling interests	(0.8)			0.3			—			(0.1)		(0.6)
Preferred stock dividends	—			—			—			28.7		28.7
Provision for income taxes(1)	—			—			—			115.9		115.9
Interest expense, net(1)	—			—			—			193.8		193.8
Depreciation and amortization	21.4			35.9			12.4			21.6		91.3
Other expense (income), net	10.3			28.5			(1.1)			(26.8)		10.9
Stock-based compensation expense(2)	2.8			2.7			1.6			14.2		21.3
Merger-related and integration costs(3)	—			—			—			30.4		30.4
Restructuring costs(4)	—			—			—			9.8		9.8
Adjusted EBITDA	$	372.0		$	335.0		$	376.3		$	(220.3)	$	863.0
Adjusted EBITDA margin %	8.6		%	9.3		%	11.2		%
(1) The reportable segments do not incur income taxes and interest expense as these costs are centrally controlled through the Corporate tax and treasury functions.
(2) Stock-based compensation expense in the calculation of adjusted EBITDA for the six months ended June 30, 2023 excludes $2.6 million that is included in merger-related and integration costs.
(3) Merger-related and integration costs include integration and professional fees associated with the integration of Wesco and Anixter, including digital transformation costs, as well as advisory, legal, and separation costs associated with the merger between the two companies.
(4) Restructuring costs include severance costs incurred pursuant to an ongoing restructuring plan.


	Six Months Ended June 30, 2022
(In millions)	EES			CSS			UBS			Corporate		Total
Net income attributable to common stockholders	$	401.5		$	234.3		$	291.8		$	(554.4)	$	373.2
Net income attributable to noncontrolling interests	0.4			—			—			0.4		0.8
Preferred stock dividends	—			—			—			28.7		28.7
Provision for income taxes(1)	—			—			—			117.6		117.6
Interest expense, net(1)	—			—			—			132.1		132.1
Depreciation and amortization	23.2			36.0			11.5			22.1		92.8
Other (income) expense, net	(1.6)			0.5			0.6			2.8		2.3
Stock-based compensation expense(2)	4.4			2.3			1.5			13.8		22.0
Merger-related and integration costs(3)	—			—			—			39.0		39.0
Adjusted EBITDA	$	427.9		$	273.1		$	305.4		$	(197.9)	$	808.5
Adjusted EBITDA margin %	9.7		%	9.0		%	10.3		%
(1) The reportable segments do not incur income taxes and interest expense as these costs are centrally controlled through the Corporate tax and treasury functions.
(2) Stock-based compensation expense in the calculation of adjusted EBITDA for the six months ended June 30, 2022 excludes $2.7 million that is included in merger-related and integration costs.
(3) Merger-related and integration costs include integration and professional fees associated with the integration of Wesco and Anixter, including digital transformation costs, as well as advisory, legal, and separation costs associated with the merger between the two companies.

GOODWILL (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
GOODWILL (Details) - USD ($) $ in Millions	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Goodwill [Line Items]
Goodwill	$ 3,266.6		$ 3,266.6		$ 3,240.9
Goodwill, Foreign Currency Translation Gain (Loss)			19.5
Goodwill, Purchase Accounting Adjustments			6.2
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	2,359.4		2,359.4		2,352.8
Finite-Lived Intangible Assets, Accumulated Amortization	(457.4)		(457.4)		(409.4)
Finite-Lived Intangible Assets, Net	1,902.0		1,902.0		1,943.4
Finite-Lived Intangible Asset, Expected Amortization, Year One	44.6		44.6
Finite-Lived Intangible Asset, Expected Amortization, Year Two	86.3		86.3
Finite-Lived Intangible Asset, Expected Amortization, Year Three	83.2		83.2
Finite-Lived Intangible Asset, Expected Amortization, Year Four	77.8		77.8
Finite-Lived Intangible Asset, Expected Amortization, Year Five	74.9		74.9
Finite-Lived Intangible Asset, Expected Amortization, after Year Five	742.2		742.2
Amortization of Intangible Assets	22.4	$ 24.7	44.4	$ 50.4
Amortization of Intangible Assets	22.4	$ 24.7	44.4	$ 50.4
Finite-Lived Intangible Asset, Expected Amortization, Year Three	83.2		83.2
Finite-Lived Intangible Asset, Expected Amortization, Year Four	77.8		77.8
Finite-Lived Intangible Asset, Expected Amortization, Year Five	74.9		74.9
Finite-Lived Intangible Asset, Expected Amortization, after Year Five	742.2		742.2
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	15.5		15.5		15.5
Finite-Lived Intangible Assets, Accumulated Amortization	(8.4)		(8.4)		(7.4)
Finite-Lived Intangible Assets, Net	$ 7.1		$ 7.1		8.1
Trademarks [Member] \| Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years		5 years
Trademarks [Member] \| Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	12 years		12 years
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 1,521.7		$ 1,521.7		1,516.0
Finite-Lived Intangible Assets, Accumulated Amortization	(423.8)		(423.8)		(377.6)
Finite-Lived Intangible Assets, Net	$ 1,097.9		$ 1,097.9		1,138.4
Customer Relationships [Member] \| Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	10 years		10 years
Customer Relationships [Member] \| Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	20 years		20 years
Distribution Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 29.2		$ 29.2		29.2
Finite-Lived Intangible Assets, Accumulated Amortization	(25.2)		(25.2)		(24.4)
Finite-Lived Intangible Assets, Net	$ 4.0		$ 4.0		4.8
Distribution Rights [Member] \| Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	15 years		15 years
Distribution Rights [Member] \| Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	19 years		19 years
EES
Goodwill [Line Items]
Goodwill	$ 837.8		$ 837.8		825.5
Goodwill, Foreign Currency Translation Gain (Loss)			12.3
Goodwill, Purchase Accounting Adjustments			0.0
CSS
Goodwill [Line Items]
Goodwill	1,216.2		1,216.2		1,208.9
Goodwill, Acquired During Period			1.1
Goodwill, Purchase Accounting Adjustments			6.2
UBS
Goodwill [Line Items]
Goodwill	1,212.6		1,212.6		1,206.5
Goodwill, Acquired During Period			6.1
Goodwill, Purchase Accounting Adjustments			0.0
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)	$ 793.0		$ 793.0		$ 792.1

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	$ 529.0	$ 527.3
Accounts Receivable, after Allowance for Credit Loss, Current	3,850.7	3,662.7
Accounts and Other Receivables, Net, Current	380.3	435.7
Inventories, net	3,584.3	3,498.8
Prepaid expenses and other current assets	239.1	206.0
Assets, Current	8,583.4	8,330.5
Property, buildings and equipment, net of accumulated depreciation of $229,041 and $213,758 in 2014 and 2013, respectively	411.3	402.7
Operating Lease, Right-of-Use Asset	681.7	625.1
Intangible assets, net	1,902.0	1,943.4
Goodwill	3,266.6	3,240.9
Other assets	317.7	269.1
Assets	15,162.7	14,811.7
Accounts payable	2,662.7	2,728.2
Accrued payroll and benefit costs	140.6	269.1
Current portion of long-term debt	9.2	70.5
Other Liabilities, Current	769.2	749.5
Liabilities, Current	3,581.7	3,817.3
Total long-term debt	5,523.1	5,346.0
Operating Lease, Liability, Noncurrent	559.3	510.4
Deferred Income Tax Liabilities, Net	477.3	460.7
Other Liabilities, Noncurrent	221.0	227.7
Liabilities	10,362.4	10,362.1
Commitments and Contingencies
Additional capital	2,015.5	2,005.4
Retained earnings	$ 4,093.4	$ 3,795.0
Treasury Stock, Common, Shares	22,211,365	22,115,653
Treasury stock, at cost; 22,211,365 and 22,115,653 shares in 2023 and 2022, respectively	$ (984.5)	$ (969.1)
Accumulated other comprehensive income	(319.5)	(377.7)
Total WESCO International, Inc. stockholders' equity	4,805.6	4,454.3
Noncontrolling interest	(5.3)	(4.7)
Total stockholders’ equity	4,800.3	4,449.6
Liabilities and Equity	$ 15,162.7	$ 14,811.7
Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares outstanding (in shares)	0	0
Preferred stock, shares issued (in shares)	0	0
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding	$ 0.0	$ 0.0
Series A Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.01
Preferred stock, shares authorized (in shares)	25,000
Preferred stock, shares outstanding (in shares)	21,612
Preferred stock, shares issued (in shares)	21,612	21,612
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding	$ 0.0	$ 0.0
Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	210,000,000	210,000,000
Common stock, shares, issued (in shares)	69,164,993	68,535,704
Common stock, shares outstanding (in shares)	51,293,059	50,759,482
Common stock	$ 0.7	$ 0.7
Common Class B [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares, issued (in shares)	4,339,431	4,339,431
Common stock, shares outstanding (in shares)	0	0
Common stock	$ 0.0	$ 0.0

DEBT (Notes)

6 Months Ended

Jun. 30, 2023

Debt Instrument [Line Items]

Debt Disclosure [Text Block]

8. DEBT

The following table sets forth Wesco's outstanding indebtedness:


	As of
	June 30, 2023		December 31, 2022
	(In millions)
International lines of credit	$	3.3	$	7.1
Accounts Receivable Securitization Facility	1,550.0		1,535.0
Revolving Credit Facility	1,175.0		1,023.6
5.50% Anixter Senior Notes due 2023	—		58.6
6.00% Anixter Senior Notes due 2025	4.2		4.2
7.125% Senior Notes due 2025	1,500.0		1,500.0
7.250% Senior Notes due 2028, less debt discount of $6.2 and $6.8 in 2023 and 2022, respectively	1,318.8		1,318.2
Finance lease obligations	25.2		20.6
Total debt	5,576.5		5,467.3
Plus: Fair value adjustments to the Anixter Senior Notes	0.1		0.3
Less: Unamortized debt issuance costs	(44.3)		(51.1)
Less: Short-term debt and current portion of long-term debt(1)	(9.2)		(70.5)
Total long-term debt	$	5,523.1	$	5,346.0

(1) As of December 31, 2022, short-term debt and current portion of long-term debt included the $58.6 million aggregate principal amount of the Company's 5.50% Anixter Senior Notes due 2023, which matured on March 1, 2023.

5.50% Anixter Senior Notes due 2023

On March 1, 2023, Wesco Distribution repaid the $58.6 million aggregate principal amount of its 5.50% Anixter Senior Notes due 2023 plus accrued interest up to, but not including, the maturity date. The repayment was funded with borrowings under the Company's Revolving Credit Facility and had no impact on the Company's results of operations.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//470/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482900/835-30-50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-3

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481568/470-20-55-69B

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69C
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481568/470-20-55-69C

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69E
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481568/470-20-55-69E

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69F
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481568/470-20-55-69F

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1D

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1D

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1D

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1F

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1F

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1F

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1F

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
INCOME TAXES (Details) - USD ($) $ in Millions	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Tax Contingency [Line Items]
Effective tax rate	27.20%	26.50%	22.90%	22.60%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Amount	$ 0.9	$ 0.3	$ 22.1	$ 6.1
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount				$ 13.4

ACCOUNTING POLICIES (Policies)	6 Months Ended
ACCOUNTING POLICIES (Policies)	Jun. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements of Wesco have been prepared in accordance with Rule 10-01 of Regulation S-X of the Securities and Exchange Commission (the “SEC”). The unaudited condensed consolidated financial information should be read in conjunction with the audited Consolidated Financial Statements and Notes thereto included in WESCO International, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2022, as filed with the SEC on February 21, 2023. The Condensed Consolidated Balance Sheet at December 31, 2022 was derived from the audited Consolidated Financial Statements as of that date, but does not include all the disclosures required by accounting principles generally accepted in the United States of America. The unaudited Condensed Consolidated Balance Sheet as of June 30, 2023, the unaudited Condensed Consolidated Statements of Income and Comprehensive Income, the unaudited Condensed Consolidated Statements of Stockholders' Equity for the three and six months ended June 30, 2023, and 2022, and the unaudited Condensed Consolidated Statements of Cash Flows for the six months ended June 30, 2023, and 2022, respectively, in the opinion of management, have been prepared on the same basis as the audited Consolidated Financial Statements and include all adjustments necessary for the fair statement of the results of the interim periods presented herein. All adjustments reflected in the unaudited condensed consolidated financial information are of a normal recurring nature unless indicated. The results for the interim periods presented herein are not necessarily indicative of the results to be expected for the full year.
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	Recently Adopted and Recently Issued Accounting Standards
New Accounting Pronouncements, Policy	Recently Adopted and Recently Issued Accounting Standards In September 2022, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2022-04, Supplier Finance Programs (Subtopic 405-50): Disclosure of Supplier Finance Program Obligations, which requires that a buyer in a supplier finance program disclose sufficient information about the program to allow a user of financial statements to understand the program's nature, activity during the period, changes from period to period, and potential magnitude. The amendments in this ASU are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, except for the amendment on rollforward information, which is effective for fiscal years beginning after December 15, 2023. The Company adopted this ASU in the first quarter of 2023, except for the amendment on rollforward information, which the Company will begin disclosing in its Annual Report on Form 10-K for the fiscal year ending December 31, 2023. The adoption of this ASU resulted in additional disclosure of the Company's supplier finance program, as described below. Other pronouncements issued by the FASB or other authoritative accounting standards groups with future effective dates are either not applicable or are not expected to be significant to Wesco’s financial position, results of operations or cash flows.

- Definition

+ References

+ Details

DEBT (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Accounts Receivable Securitization Facility
Debt Instrument [Line Items]
Long-term Debt	$ 1,550.0	$ 1,535.0
Revolving Credit Facility
Debt Instrument [Line Items]
Long-term Debt	1,175.0	1,023.6
5.50% Senior Notes due 2023
Debt Instrument [Line Items]
Long-term Debt	0.0	58.6
6.00% Senior Notes due 2025
Debt Instrument [Line Items]
Long-term Debt	4.2	4.2
7.125% Senior Notes due 2025
Debt Instrument [Line Items]
Long-term Debt	1,500.0	1,500.0
7.250% Senior Notes due 2028
Debt Instrument [Line Items]
Long-term Debt	$ 1,318.8	$ 1,318.2

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References + Details

ACCOUNTING POLICIES (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Accounting Policies [Abstract]
Supplier Finance Program, Obligation	$ 29.4				$ 29.4		$ 30.7
Common Stock, Dividends, Per Share, Declared	$ 0.375	$ 0.375
Dividends, Preferred Stock	$ 14.4	$ 14.4	$ 14.4	$ 14.4		$ 28.7
Preferred Stock, Dividends Per Share, Declared					$ 0.664

EARNINGS PER SHARE (Details) - shares shares in Millions	6 Months Ended
EARNINGS PER SHARE (Details) - shares shares in Millions	Jun. 30, 2023	Jun. 30, 2022
Stock Appreciation Rights (SARs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0.4	0.1

FAIR VALUE (Notes)	6 Months Ended
FAIR VALUE (Notes)	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	10. FAIR VALUE OF FINANCIAL INSTRUMENTS The Company’s financial instruments primarily consist of cash and cash equivalents, accounts receivable, accounts payable, bank overdrafts, outstanding indebtedness, foreign currency forward contracts, and benefit plan assets. Except for benefit plan assets, outstanding indebtedness and foreign currency forward contracts, the carrying value of the Company’s other financial instruments approximates fair value. The assets of the Company's various defined benefit plans are primarily comprised of common/collective/pool funds (i.e., mutual funds). These funds are valued at the net asset value (NAV) of shares held in the underlying funds. Investments for which fair value is measured using the NAV per share practical expedient are not classified in the fair value hierarchy. The Company uses a market approach to determine the fair value of its debt instruments, utilizing quoted prices in active markets, interest rates and other relevant information generated by market transactions involving similar instruments. Therefore, the inputs used to measure the fair value of the Company's debt instruments are classified as Level 2 within the fair value hierarchy. The carrying value of Wesco's debt instruments with fixed interest rates was $2,823.1 million and $2,881.2 million as of June 30, 2023 and December 31, 2022, respectively. The estimated fair value of this debt was $2,876.3 million and $2,929.5 million as of June 30, 2023 and December 31, 2022, respectively. The reported carrying values of Wesco's other debt instruments, including those with variable interest rates, approximated their fair values as of June 30, 2023 and December 31, 2022. The Company purchases foreign currency forward contracts to reduce the effect of fluctuations in foreign currency-denominated accounts on its earnings. The foreign currency forward contracts are not designated as hedges for accounting purposes. The Company's strategy is to negotiate terms for its derivatives and other financial instruments to be highly effective, such that the change in the value of the derivative offsets the impact of the underlying hedge. Its counterparties to foreign currency forward contracts have investment-grade credit ratings. The Company regularly monitors the creditworthiness of its counterparties to ensure no issues exist that could affect the value of its derivatives. The Company does not hedge 100% of its foreign currency-denominated accounts. In addition, the results of hedging can vary significantly based on various factors, such as the timing of executing foreign currency forward contracts versus the movement of currencies, as well as fluctuations in the account balances throughout each reporting period. The fair value of foreign currency forward contracts is based on the difference between the contract rate and the current price of a forward contract with an equivalent remaining term. The fair value of foreign currency forward contracts is measured using observable market information. These inputs are considered Level 2 in the fair value hierarchy. At June 30, 2023 and December 31, 2022, foreign currency forward contracts were revalued at then-current foreign exchange rates with the changes in valuation reflected directly in other non-operating expense (income) in the Condensed Consolidated Statements of Income and Comprehensive Income offsetting the transaction gain (loss) recorded on foreign currency-denominated accounts. The gross and net notional amounts of foreign currency forward contracts outstanding were approximately $132.9 million and $172.8 million, at June 30, 2023 and December 31, 2022, respectively. While all of the Company's foreign currency forward contracts are subject to master netting arrangements with its counterparties, assets and liabilities related to these contracts are presented on a gross basis within the Condensed Consolidated Balance Sheets. The gross fair value of assets and liabilities related to foreign currency forward contracts were immaterial.
Derivatives and Fair Value	The Company purchases foreign currency forward contracts to reduce the effect of fluctuations in foreign currency-denominated accounts on its earnings. The foreign currency forward contracts are not designated as hedges for accounting purposes. The Company's strategy is to negotiate terms for its derivatives and other financial instruments to be highly effective, such that the change in the value of the derivative offsets the impact of the underlying hedge. Its counterparties to foreign currency forward contracts have investment-grade credit ratings. The Company regularly monitors the creditworthiness of its counterparties to ensure no issues exist that could affect the value of its derivatives. The Company does not hedge 100% of its foreign currency-denominated accounts. In addition, the results of hedging can vary significantly based on various factors, such as the timing of executing foreign currency forward contracts versus the movement of currencies, as well as fluctuations in the account balances throughout each reporting period. The fair value of foreign currency forward contracts is based on the difference between the contract rate and the current price of a forward contract with an equivalent remaining term. The fair value of foreign currency forward contracts is measured using observable market information. These inputs are considered Level 2 in the fair value hierarchy. At June 30, 2023 and December 31, 2022, foreign currency forward contracts were revalued at then-current foreign exchange rates with the changes in valuation reflected directly in other non-operating expense (income) in the Condensed Consolidated Statements of Income and Comprehensive Income offsetting the transaction gain (loss) recorded on foreign currency-denominated accounts. The gross and net notional amounts of foreign currency forward contracts outstanding were approximately $132.9 million and $172.8 million, at June 30, 2023 and December 31, 2022, respectively. While all of the Company's foreign currency forward contracts are subject to master netting arrangements with its counterparties, assets and liabilities related to these contracts are presented on a gross basis within the Condensed Consolidated Balance Sheets. The gross fair value of assets and liabilities related to foreign currency forward contracts were immaterial.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

SCHEDULE OF DEBT (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Finance lease obligations	$ 25.2	$ 20.6
Total debt	5,576.5	5,467.3
Fair value adjustment to the Anixter Notes	0.1	0.3
Unamortized debt issuance costs	(44.3)	(51.1)
Short-term debt and current portion of long-term debt	(9.2)	(70.5)
Total long-term debt	5,523.1	5,346.0
Foreign Line of Credit
Debt Instrument [Line Items]
Long-term Debt	3.3	7.1
Accounts Receivable Securitization Facility
Debt Instrument [Line Items]
Long-term Debt	1,550.0	1,535.0
Revolving Credit Facility
Debt Instrument [Line Items]
Long-term Debt	1,175.0	1,023.6
5.50% Senior Notes due 2023
Debt Instrument [Line Items]
Long-term Debt	0.0	58.6
6.00% Senior Notes due 2025
Debt Instrument [Line Items]
Long-term Debt	4.2	4.2
7.125% Senior Notes due 2025
Debt Instrument [Line Items]
Long-term Debt	1,500.0	1,500.0
7.250% Senior Notes due 2028
Debt Instrument [Line Items]
Long-term Debt	1,318.8	1,318.2
Debt Instrument, Unamortized Discount	$ 6.2	$ 6.8

SCHEDULE OF SHARE-BASED COMPENSATION, STOCK OPTIONS AND STOCK APPRECIATION RIGHTS AWARD ACTIVITY (Details) - Stock Appreciation Rights (SARs) [Member] - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	840,852	1,248,115
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 59.71	$ 62.02
Granted (in shares)	0
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Exercised	(406,625)
Weighted Average Exercise Price, Exercises in Period (in dollars per share)	$ 66.80
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures	(638)
Weighted Average Exercise Price, Forfeitures in Period (in dollars per share)	$ 72.15
Weighted Average Remaining Contractual Term, Outstanding (in years)	5 years 6 months
Aggregate Intrinsic Value, Outstanding	$ 100.4
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number	799,354
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 58.81
Weighted Average Remaining Contractual Term, Exercisable (in years)	5 years 4 months 24 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 96.1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 37.9

REVENUE (Notes)

6 Months Ended

Jun. 30, 2023

Revenue from Contract with Customer [Abstract]

Revenue from Contract with Customer

3. REVENUE

Wesco distributes products and provides services to customers globally in various end markets within its business segments. The segments operate in the United States, Canada and various other countries.

The following tables disaggregate Wesco’s net sales by segment and geography for the periods presented:


	Three Months Ended				Six Months Ended
	June 30				June 30
(In millions)	2023		2022		2023		2022
Electrical & Electronic Solutions	$	2,200.3	$	2,330.1	$	4,335.4	$	4,420.1
Communications & Security Solutions	1,850.9		1,602.0		3,582.9		3,036.2
Utility & Broadband Solutions	1,694.3		1,551.4		3,349.1		2,959.4
Total by segment	$	5,745.5	$	5,483.5	$	11,267.4	$	10,415.7


	Three Months Ended				Six Months Ended
	June 30				June 30
(In millions)	2023		2022		2023		2022
United States	$	4,272.5	$	4,039.9	$	8,363.0	$	7,694.1
Canada	773.1		807.8		1,532.5		1,522.9
Other International(1)	699.9		635.8		1,371.9		1,198.7
Total by geography(2)	$	5,745.5	$	5,483.5	$	11,267.4	$	10,415.7

(1) No individual country's net sales are greater than 10% of total net sales.

(2) Wesco attributes revenues from external customers to individual countries on the basis of point of sale.

Due to the terms of certain contractual arrangements, Wesco bills or receives payment from its customers in advance of satisfying the respective performance obligation. Such advance billings or payments are recorded as deferred revenue and recognized as revenue when the performance obligation has been satisfied and control has transferred to the customer, which is generally upon shipment. Deferred revenue is usually recognized within a year or less from the date of the advance billing or payment. At June 30, 2023 and December 31, 2022, $104.8 million and $99.6 million, respectively, of deferred revenue was recorded as a component of other current liabilities in the Condensed Consolidated Balance Sheets. The Company recognized $21.0 million and $42.0 million of revenue during the three and six months ended June 30, 2023, respectively, that was included in the deferred revenue balance as of December 31, 2022. The amount of revenue recognized during the three and six months ended June 30, 2022 that was deferred as of December 31, 2021 was not material.

The Company also has certain long-term contractual arrangements where revenue is recognized over time based on the cost-to-cost input method. As of June 30, 2023 and December 31, 2022, the Company had contract assets of $40.7 million and $27.5 million, respectively, resulting from contracts where the amount of revenue recognized exceeded the amount billed to the customer. Contract assets are recorded in the Condensed Consolidated Balance Sheets as a component of prepaid expenses and other current assets.

Wesco’s revenues are adjusted for variable consideration, which includes customer volume rebates, returns and discounts. Wesco measures variable consideration by estimating expected outcomes using analysis and inputs based upon historical data, as well as current and forecasted information. Variable consideration is reviewed by management on a monthly basis and revenue is adjusted accordingly. Variable consideration reduced revenue for the three months ended June 30, 2023 and 2022 by approximately $118.5 million and $108.5 million, respectively, and by approximately $215.0 million and $203.6 million for the six months ended June 30, 2023 and 2022, respectively. The variable consideration for the three months ended June 30, 2022 reflects an adjustment that increased the previously disclosed amount by $6.2 million and the variable consideration for the six months ended June 30, 2022 reflects an adjustment that reduced the previously disclosed amount by $13.9 million. As of June 30, 2023 and December 31, 2022, the Company's estimated product return obligation was $41.9 million and $46.5 million, respectively.

Billings to customers for shipping and handling are recognized in net sales. Wesco has elected to recognize shipping and handling costs as a fulfillment cost. Shipping and handling costs recorded as a component of selling, general and administrative expenses totaled $79.1 million and $76.5 million for the three months ended June 30, 2023 and 2022, respectively, and $156.0 million and $144.1 million for the six months ended June 30, 2023 and 2022, respectively.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-9

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-10

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-15

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-13

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Topic 606
-Publisher FASB
-URI https://asc.fasb.org//606/tableOfContent

+ Details

REVENUE (Tables)

6 Months Ended

Jun. 30, 2023

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue [Table Text Block]

The following tables disaggregate Wesco’s net sales by segment and geography for the periods presented:


	Three Months Ended				Six Months Ended
	June 30				June 30
(In millions)	2023		2022		2023		2022
Electrical & Electronic Solutions	$	2,200.3	$	2,330.1	$	4,335.4	$	4,420.1
Communications & Security Solutions	1,850.9		1,602.0		3,582.9		3,036.2
Utility & Broadband Solutions	1,694.3		1,551.4		3,349.1		2,959.4
Total by segment	$	5,745.5	$	5,483.5	$	11,267.4	$	10,415.7


	Three Months Ended				Six Months Ended
	June 30				June 30
(In millions)	2023		2022		2023		2022
United States	$	4,272.5	$	4,039.9	$	8,363.0	$	7,694.1
Canada	773.1		807.8		1,532.5		1,522.9
Other International(1)	699.9		635.8		1,371.9		1,198.7
Total by geography(2)	$	5,745.5	$	5,483.5	$	11,267.4	$	10,415.7

STOCK-BASED COMPENSATION AWARDS (Details) - $ / shares	3 Months Ended		6 Months Ended
STOCK-BASED COMPENSATION AWARDS (Details) - $ / shares	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			0
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	3,295	0	173,864	224,946
Granted, Weighted Average Fair Value (in dollars per share)	$ 138.11	$ 0	$ 170.41	$ 122.11
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	3,074	0	211,445	83,991
Granted, Weighted Average Fair Value (in dollars per share)	$ 150.32	$ 0	$ 86.88	$ 122.09
Performance Shares [Member] \| 2020 Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			144,697
Granted, Weighted Average Fair Value (in dollars per share)			$ 48.32
Performance Shares [Member] \| 2023 Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			63,098
Granted, Weighted Average Fair Value (in dollars per share)			$ 171.96
Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	1,954	0	77,136	89,550
Granted, Weighted Average Fair Value (in dollars per share)	$ 76.75	$ 0	$ 76.77	$ 57.26

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Business Combinations and Asset Acquisitions	6 Months Ended
Business Combinations and Asset Acquisitions	Jun. 30, 2023
Business Combination and Asset Acquisition [Abstract]
Business Combination Disclosure	Rahi Systems Holdings, Inc. On November 1, 2022, through its wholly-owned subsidiary WESCO Distribution, Inc. (“Wesco Distribution”), the Company acquired 100% of the equity securities of Rahi Systems Holdings, Inc. (“Rahi Systems” or “Rahi”). Headquartered in Fremont, California, Rahi Systems is a leading provider of global hyperscale data center solutions with over 900 employees in 25 countries. Rahi's expertise with complex information technology projects and global presence strengthen Wesco's data center solution offerings. Wesco Distribution funded the purchase price paid at closing with cash on hand as well as borrowings under its accounts receivable securitization and revolving credit facilities. Since the initial measurement of the identified assets acquired and liabilities assumed, the Company has recorded adjustments to inventories of $21.8 million and accounts payable of $28.0 million. The net impact of these adjustments was an increase to goodwill of $6.2 million. The estimated fair values of assets acquired and liabilities assumed are based on preliminary calculations and valuations using estimates and assumptions at the time of acquisition. As the Company obtains additional information during the measurement period (not to exceed one year from the acquisition date), estimates and assumptions for the preliminary purchase consideration allocations may change materially. The results of operations of Rahi Systems are included in Wesco's unaudited Condensed Consolidated Financial Statements beginning on November 1, 2022, the acquisition date. For the three and six months ended June 30, 2023, the Condensed Consolidated Statement of Income includes $150.3 million and $286.6 million of net sales, respectively, and an immaterial amount of income from operations for Rahi Systems. The Company has not presented supplemental pro forma revenue and earnings of the combined business as the acquisition of Rahi Systems is not material to Wesco's unaudited Condensed Consolidated Financial Statements.

EMPLOYEE BENEFIT PLANS Schedule of Net Benefit Costs (Tables)

6 Months Ended

Jun. 30, 2023

Postemployment Benefits [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

The following table sets forth the components of net periodic pension (benefit) cost for the Company's defined benefit plans:


	Three Months Ended
(In millions)	June 30, 2023		June 30, 2022		June 30, 2023		June 30, 2022		June 30, 2023		June 30, 2022
	Domestic Plans(1)				Foreign Plans(2)				Total
Service cost	$	—	$	—	$	1.2	$	2.1	$	1.2	$	2.1
Interest cost	0.6		2.1		2.9		2.3		3.5		4.4
Expected return on plan assets	(0.6)		(3.5)		(3.0)		(4.2)		(3.6)		(7.7)
Recognized actuarial gain(3)	—		—		(0.3)		(0.2)		(0.3)		(0.2)
Net periodic pension (benefit) cost	$	—	$	(1.4)	$	0.8	$	—	$	0.8	$	(1.4)


	Six Months Ended
(In millions)	June 30, 2023		June 30, 2022		June 30, 2023		June 30, 2022		June 30, 2023		June 30, 2022
	Domestic Plans(1)				Foreign Plans(2)				Total
Service cost	$	—	$	—	$	2.4	$	4.3	$	2.4	$	4.3
Interest cost	3.2		4.2		5.7		4.6		8.9		8.8
Expected return on plan assets	(3.0)		(7.0)		(6.0)		(8.5)		(9.0)		(15.5)
Recognized actuarial gain(3)	—		—		(0.6)		(0.4)		(0.6)		(0.4)
Net periodic pension (benefit) cost	$	0.2	$	(2.8)	$	1.5	$	—	$	1.7	$	(2.8)

(1) Defined as the Anixter Inc. Pension Plan, Anixter Inc. Executive Benefit Plan, and the Anixter Inc. Supplemental Executive Retirement Plan.

(3) For the three and six months ended June 30, 2023 and 2022, no material amounts were reclassified from accumulated other comprehensive income into net income.

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Operating Activities:
Net income	$ 389.6	$ 402.7
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	91.3	92.8
Stock-based compensation expense	23.9	24.7
Amortization of Debt Issuance Costs and Discounts	7.4	8.1
Deferred income taxes	16.2	1.3
Other operating activities, net	1.0	2.9
Changes in assets and liabilities
Increase (Decrease) in Accounts Receivable	162.9	716.8
Increase (Decrease) in Accounts and Other Receivables	55.7	(15.3)
Inventories, net	(73.9)	(530.8)
Increase (Decrease) in Other Operating Assets	(56.9)	(80.7)
Accounts payable	(78.6)	534.3
Accrued payroll and benefit costs	(134.1)	(115.8)
Other current and noncurrent liabilities	(16.5)	88.1
Net cash provided by operating activities	62.2	(304.5)
Investing Activities:
Capital expenditures	(44.3)	(31.6)
Other investing activities	0.6	0.6
Net cash used in investing activities	(43.7)	(31.0)
Financing Activities:
Proceeds from (Repayments of) Short-term Debt	(3.6)	2.2
Repayments of Senior Debt	58.6	0.0
Proceeds from issuance of long-term debt	1,596.2	1,746.3
Repayments of Other Long-term Debt	1,429.8	1,354.0
Payments for Repurchase of Common Stock	(54.2)	(17.2)
Payments of Ordinary Dividends, Preferred Stock and Preference Stock	28.7	28.7
Payments of Ordinary Dividends, Common Stock	(38.4)	0.0
Other financing activities, net	(3.3)	(8.1)
Net cash used in financing activities	(20.4)	340.5
Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations	3.6	19.2
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Total	1.7	24.2
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	529.0	236.8
Supplemental Cash Flow Information [Abstract]
Interest Paid, Excluding Capitalized Interest, Operating Activities	187.7	119.3
Income Taxes Paid	108.3	155.0
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 120.8	$ 117.9

DEBT (Tables)

6 Months Ended

Jun. 30, 2023

Debt Disclosure [Abstract]

Schedule of Debt

The following table sets forth Wesco's outstanding indebtedness:


	As of
	June 30, 2023		December 31, 2022
	(In millions)
International lines of credit	$	3.3	$	7.1
Accounts Receivable Securitization Facility	1,550.0		1,535.0
Revolving Credit Facility	1,175.0		1,023.6
5.50% Anixter Senior Notes due 2023	—		58.6
6.00% Anixter Senior Notes due 2025	4.2		4.2
7.125% Senior Notes due 2025	1,500.0		1,500.0
7.250% Senior Notes due 2028, less debt discount of $6.2 and $6.8 in 2023 and 2022, respectively	1,318.8		1,318.2
Finance lease obligations	25.2		20.6
Total debt	5,576.5		5,467.3
Plus: Fair value adjustments to the Anixter Senior Notes	0.1		0.3
Less: Unamortized debt issuance costs	(44.3)		(51.1)
Less: Short-term debt and current portion of long-term debt(1)	(9.2)		(70.5)
Total long-term debt	$	5,523.1	$	5,346.0

5.50% Anixter Senior Notes due 2023

COVER PAGE - shares	6 Months Ended
COVER PAGE - shares	Jun. 30, 2023	Aug. 04, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	001-14989
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	25-1723342
Entity Address, Address Line One	225 West Station Square DriveSuite 700
Entity Address, City or Town	Pittsburgh,
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	15219
City Area Code	412
Local Phone Number	454-2200
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Registrant Name	WESCO International, Inc.
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Current Reporting Status	Yes
Entity Central Index Key	0000929008
Entity Common Stock, Shares Outstanding		51,394,210
Entity Listings [Line Items]
Entity Common Stock, Shares Outstanding		51,394,210
Common Class A [Member]
Cover [Abstract]
Title of 12(b) Security	Common Stock, par value $.01 per share
Trading Symbol	WCC
Security Exchange Name	NYSE
Entity Listings [Line Items]
Title of 12(b) Security	Common Stock, par value $.01 per share
Trading Symbol	WCC
Security Exchange Name	NYSE
Series A Preferred Stock [Member]
Cover [Abstract]
Title of 12(b) Security	Depositary Shares, each representing a 1/1,000th interest in a share of Series A Fixed-Rate Reset Cumulative Perpetual Preferred Stock
Trading Symbol	WCC PR A
Security Exchange Name	NYSE
Entity Listings [Line Items]
Title of 12(b) Security	Depositary Shares, each representing a 1/1,000th interest in a share of Series A Fixed-Rate Reset Cumulative Perpetual Preferred Stock
Trading Symbol	WCC PR A
Security Exchange Name	NYSE

CONSOLIDATED BALANCE SHEETS (parenthetical items) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Accounts Receivable, Allowance for Credit Loss, Current	$ 57.5	$ 46.5
Accumulated depreciation	473.0	425.8
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	$ 50.5	$ 57.9

REVENUE Revenue, Performance Obligation (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue from Contract with Customer [Abstract]
Cost of goods sold	$ 4,503.1	$ 4,294.1	$ 8,816.5	$ 8,177.2

Compensation Related Costs, Postemployment Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Defined Contribution Plan Disclosure [Line Items]
Service cost	$ 1.2	$ 2.1	$ 2.4	$ 4.3
Interest cost	3.5	4.4	8.9	8.8
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	3.6	7.7	9.0	15.5
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	0.3	0.2	0.6	0.4
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	0.8	(1.4)	1.7	(2.8)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	4.3		6.7
WESCODeferredCompensationPlanMember
Defined Contribution Plan Disclosure [Line Items]
Deferred Compensation Liability, Classified, Noncurrent	26.6		26.6		$ 20.3
Pension Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other Nonoperating Gains (Losses)	(0.5)	(3.5)	(0.7)	(7.1)
UNITED STATES
Defined Contribution Plan Disclosure [Line Items]
Service cost	0.0	0.0	0.0	0.0
Interest cost	0.6	2.1	3.2	4.2
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	0.6	3.5	3.0	7.0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	0.0	0.0	0.0	0.0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	0.0	(1.4)	0.2	(2.8)
Foreign Plan
Defined Contribution Plan Disclosure [Line Items]
Service cost	1.2	2.1	2.4	4.3
Interest cost	2.9	2.3	5.7	4.6
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	3.0	4.2	6.0	8.5
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	0.3	0.2	0.6	0.4
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 0.8	$ 0.0	$ 1.5	$ 0.0

Segment Reporting - ADJ EBITDA Reconciliations (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Net Income (Loss) Available to Common Stockholders, Basic	$ 178.7		$ 206.3		$ 361.5	$ 373.2
Net (loss) income attributable to noncontrolling interest	(0.7)	$ 0.1	0.4	$ 0.4	(0.6)	0.8
Preferred Stock Dividends, Income Statement Impact	14.4		14.4		28.7	28.7
Provision for income taxes	71.8		79.9		115.9	117.6
Interest Income (Expense), Nonoperating, Net	(98.8)		(68.5)		(193.8)	(132.1)
Depreciation and amortization	46.9		45.8		91.3	92.8
Other Nonoperating Income (Expense)	(0.8)		(1.2)		(10.9)	(2.3)
StockBasedCompensationExpenseEBITDA	10.9		14.5		21.3	22.0
MergerRelatedAndIntegrationCosts	10.9		13.4		30.4	39.0
Restructuring Costs	9.8				9.8
Adjusted EBITDA	442.3		444.4		863.0	808.5
Stock-based compensation expense	$ 12.2		15.8		23.9	24.7
Adjusted EBITDA Margin %	11.10%
Merger Related Stock Based Compensation Expense	$ 1.3		1.4		2.6	2.7
EES
Net Income (Loss) Available to Common Stockholders, Basic	167.0		222.8		338.3	401.5
Net (loss) income attributable to noncontrolling interest	(0.7)		0.1		(0.8)	0.4
Preferred Stock Dividends, Income Statement Impact	0.0		0.0		0.0	0.0
Provision for income taxes	0.0		0.0		0.0	0.0
Interest Income (Expense), Nonoperating, Net	0.0		0.0		0.0	0.0
Depreciation and amortization	11.5		11.2		21.4	23.2
Other Nonoperating Income (Expense)	9.8		1.4		10.3	(1.6)
StockBasedCompensationExpenseEBITDA	1.4		2.7		2.8	4.4
MergerRelatedAndIntegrationCosts	0.0		0.0		0.0	0.0
Restructuring Costs	0.0				0.0
Adjusted EBITDA	$ 189.0		$ 235.4		$ 372.0	$ 427.9
Adjusted EBITDA Margin %	8.60%		10.10%		8.60%	9.70%
CSS
Net Income (Loss) Available to Common Stockholders, Basic	$ 132.2		$ 130.6		$ 267.6	$ 234.3
Net (loss) income attributable to noncontrolling interest	0.1		0.0		0.3	0.0
Preferred Stock Dividends, Income Statement Impact	0.0		0.0		0.0	0.0
Provision for income taxes	0.0		0.0		0.0	0.0
Interest Income (Expense), Nonoperating, Net	0.0		0.0		0.0	0.0
Depreciation and amortization	17.9		17.9		35.9	36.0
Other Nonoperating Income (Expense)	27.7		(0.1)		28.5	0.5
StockBasedCompensationExpenseEBITDA	1.6		1.4		2.7	2.3
MergerRelatedAndIntegrationCosts	0.0		0.0		0.0	0.0
Restructuring Costs	0.0				0.0
Adjusted EBITDA	$ 179.5		$ 150.0		$ 335.0	$ 273.1
Adjusted EBITDA Margin %	9.70%		9.40%		9.30%	9.00%
UBS
Net Income (Loss) Available to Common Stockholders, Basic	$ 183.1		$ 161.8		$ 363.4	$ 291.8
Net (loss) income attributable to noncontrolling interest	0.0		0.0		0.0	0.0
Preferred Stock Dividends, Income Statement Impact	0.0		0.0		0.0	0.0
Provision for income taxes	0.0		0.0		0.0	0.0
Interest Income (Expense), Nonoperating, Net	0.0		0.0		0.0	0.0
Depreciation and amortization	6.4		5.7		12.4	11.5
Other Nonoperating Income (Expense)	(1.7)		(0.6)		(1.1)	0.6
StockBasedCompensationExpenseEBITDA	0.8		0.9		1.6	1.5
MergerRelatedAndIntegrationCosts	0.0		0.0		0.0	0.0
Restructuring Costs	0.0				0.0
Adjusted EBITDA	$ 188.6		$ 169.0		$ 376.3	$ 305.4
Adjusted EBITDA Margin %	11.10%		10.90%		11.20%	10.30%
Corporate Segment
Net Income (Loss) Available to Common Stockholders, Basic	$ (303.6)		$ (308.9)		$ (607.8)	$ (554.4)
Net (loss) income attributable to noncontrolling interest	(0.1)		0.3		(0.1)	0.4
Preferred Stock Dividends, Income Statement Impact	14.4		14.4		28.7	28.7
Provision for income taxes	71.8		79.9		115.9	117.6
Interest Income (Expense), Nonoperating, Net	98.8		(68.5)		193.8	132.1
Depreciation and amortization	11.1		11.0		21.6	22.1
Other Nonoperating Income (Expense)	(35.0)		(1.9)		(26.8)	2.8
StockBasedCompensationExpenseEBITDA	7.1		9.5		14.2	13.8
MergerRelatedAndIntegrationCosts	10.9		13.4		30.4	39.0
Restructuring Costs	9.8				9.8
Adjusted EBITDA	$ (114.8)		$ (110.0)		$ (220.3)	$ (197.9)

INCOME TAXES	6 Months Ended
INCOME TAXES	Jun. 30, 2022
Income Tax Disclosure [Abstract]
INCOME TAXES	The effective tax rate for the three months ended June 30, 2023 and 2022 was 27.2% and 26.5%, respectively. For the three months ended June 30, 2023 and 2022, the effective tax rates reflect discrete income tax benefits of $0.9 million and $0.3 million, respectively, resulting from the exercise and vesting of stock-based awards. These discrete income tax benefits reduced the effective tax rates in such periods by approximately 0.3 and 0.1 percentage points, respectively. The effective tax rate for the six months ended June 30, 2023 and 2022 was 22.9% and 22.6%, respectively. For the six months ended June 30, 2023 and 2022, the effective tax rates reflect discrete income tax benefits of $22.1 million and $6.1 million, respectively, resulting from the exercise and vesting of stock-based awards. For the six months ended June 30, 2022, the effective tax rate also reflects a discrete income tax benefit of $13.4 million resulting from a reduction to the valuation allowance recorded against foreign tax credit carryforwards. These discrete income tax benefits reduced the effective tax rates in such periods by approximately 4.4 and 3.7 percentage points, respectively. The effective tax rate differs from the federal statutory income tax rate due primarily to state income taxes, nondeductible expenses, and the inclusion of global intangible low-taxed income. There have been no material adjustments to liabilities for uncertain tax positions since December 31, 2022.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details