REVENUE (Tables)

6 Months Ended

Jun. 30, 2018

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue [Table Text Block]

The following tables disaggregate WESCO’s revenue by end market and geography:



	Three Months Ended				Six Months Ended
	June 30				June 30
(In thousands)	2018		2017		2018		2017
Industrial	$	760,741	$	711,305	$	1,519,723	$	1,389,601
Construction	683,752		623,763		1,321,551		1,195,392
Utility	336,961		282,400		652,506		548,660
Commercial, Institutional and Government ("CIG")	322,540		292,156		604,129		548,562
Total by end market	$	2,103,994	$	1,909,624	$	4,097,909	$	3,682,215



	Three Months Ended				Six Months Ended
	June 30				June 30
(In thousands)	2018		2017		2018		2017
United States	$	1,563,392	$	1,451,401	$	3,046,140	$	2,794,601
Other ⁽¹⁾	540,602		458,223		1,051,769		887,614
Total by geography	$	2,103,994	$	1,909,624	$	4,097,909	$	3,682,215


⁽¹⁾	Other primarily includes net sales to customers in Canada.

Revenue Recognition, Revenue Reductions [Policy Text Block]

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 anticipated performance, historical data, as well as current and forecasted information. Measurement and recognition of 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, 2018 and 2017 by approximately $25.0 million and $21.7 million, respectively, and by approximately $49.4 million and $42.3 million for the six months ended June 30, 2018 and 2017, respectively.