INCOME TAXES	3 Months Ended
Mar. 31, 2017
Income Tax Disclosure [Abstract]
INCOME TAXES	9. INCOME TAXES The effective tax rate for the three months ended March 31, 2017 and 2016 was 25.0% and 31.9%, respectively. WESCO’s effective tax rate is lower than the federal statutory rate of 35% due to benefits resulting from the tax effect of intercompany financing and lower rates on foreign earnings, which are partially offset by nondeductible expenses and state taxes. In the current quarter, the application of Accounting Standards Update No. 2016-09 resulted in a discrete benefit from the exercise and vesting of stock-based awards, which lowered the effective tax rate by 3.1 percentage points. In the first quarter of 2016, the settlement of an outstanding tax matter increased the effective tax rate by 3.4 percentage points. The total amount of unrecognized tax benefits was reduced by $0.7 million during the three months ended March 31, 2017 to $5.5 million due to the expiration of statutes of limitation. At March 31, 2017, the amount of unrecognized tax benefits that would affect the effective tax rate if recognized in the consolidated financial statements was $6.8 million. Within the next twelve months, it is reasonably possible that the amount of unrecognized tax benefits will decrease by approximately $0.2 million due to the expiration of statutes of limitation. Such change could impact the effective tax rate by the same amount.

INCOME TAXES

3 Months Ended

Mar. 31, 2017

9. INCOME TAXES

The effective tax rate for the three months ended March 31, 2017 and 2016 was 25.0% and 31.9%, respectively. WESCO’s effective tax rate is lower than the federal statutory rate of 35% due to benefits resulting from the tax effect of intercompany financing and lower rates on foreign earnings, which are partially offset by nondeductible expenses and state taxes. In the current quarter, the application of Accounting Standards Update No. 2016-09 resulted in a discrete benefit from the exercise and vesting of stock-based awards, which lowered the effective tax rate by 3.1 percentage points. In the first quarter of 2016, the settlement of an outstanding tax matter increased the effective tax rate by 3.4 percentage points.

The total amount of unrecognized tax benefits was reduced by $0.7 million during the three months ended March 31, 2017 to $5.5 million due to the expiration of statutes of limitation. At March 31, 2017, the amount of unrecognized tax benefits that would affect the effective tax rate if recognized in the consolidated financial statements was $6.8 million. Within the next twelve months, it is reasonably possible that the amount of unrecognized tax benefits will decrease by approximately $0.2 million due to the expiration of statutes of limitation. Such change could impact the effective tax rate by the same amount.