INCOME TAXES	6 Months Ended
	Jun. 30, 2021
Income Tax Disclosure [Abstract]
INCOME TAXES	The effective tax rate for the three and six months ended June 30, 2021 was 21.6% and 18.1%, respectively. The effective tax rate for the three and six months ended June 30, 2020 was 24.0% and 67.3%, respectively. WESCO’s effective tax rate typically differs from the federal statutory income tax rate due to the tax effect of intercompany financing, foreign tax rate differences, the U.S. taxes imposed on foreign income, nondeductible expenses and state income taxes. The effective tax rate for the three months ended June 30, 2021 is lower than the corresponding quarter of the prior year primarily due to a discrete income tax benefit of $3.4 million associated with the exercise and vesting of stock-based awards. For the six months ended June 30, 2021, the effective tax rate is lower than the corresponding year-to-date period of the preceding year primarily due to the discrete income tax benefits of $8.3 million resulting from a change in the valuation allowance recorded against foreign tax credit carryforwards, and $4.5 million associated with the exercise and vesting of stock-based awards. In addition, the effective tax rates for the prior year periods were higher due to costs incurred to complete the acquisition of Anixter. There have been no material adjustments to liabilities for uncertain tax positions since the last annual disclosure for the year ended December 31, 2020.