CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Gross Profit [Abstract]
Revenues	$ 4,595,790	$ 2,086,706	$ 8,637,267	$ 4,055,353
Cost of goods sold	3,630,633	1,692,931	6,861,074	3,285,179
Operating Expenses [Abstract]
Selling, general and administrative expense	699,581	359,750	1,336,157	659,143
Depreciation and amortization	46,704	18,755	87,913	34,848
Income from operations	218,872	15,270	352,123	76,183
Nonoperating Income (Expense)	67,590	61,270	137,963	77,862
Other Nonoperating Income (Expense)	(802)	(687)	(3,609)	(807)
Income before income taxes	152,084	(45,313)	217,769	(872)
Provision for income taxes	32,800	(10,854)	39,331	(587)
Net income	119,284	(34,459)	178,438	(285)
Net (loss) income attributable to noncontrolling interest	89	47	65	(185)
Net income attributable to WESCO International, Inc.	119,195	(34,506)	178,373	(100)
Preferred Stock Dividends, Income Statement Impact	14,352	1,276	28,704	1,276
Net Income (Loss) Available to Common Stockholders, Basic	104,843	(35,782)	149,669	(1,376)
Comprehensive Income:
Foreign currency translation adjustment	21,219	42,734	38,060	(51,117)
Comprehensive income attributable to WESCO International, Inc.	$ 126,062	$ 6,952	$ 187,729	$ (52,493)
Basic (in dollars per share)	$ 2.09	$ (0.84)	$ 2.98	$ (0.03)
Diluted (in dollars per share)	$ 2.02	$ (0.84)	$ 2.89	$ (0.03)