OTHER FINANCIAL INFORMATION (Tables)

12 Months Ended

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Condensed Financial Information [Abstract]

Condensed Balance Sheet [Table Text Block]



	Condensed Consolidating Balance Sheet
	December 31, 2016
	(In thousands)
	WESCO International, Inc.		WESCO Distribution, Inc.		Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Cash and cash equivalents	$	—	$	41,552	$	68,579		$	—		$	110,131
Trade accounts receivable, net	—		—		1,034,402			—			1,034,402
Inventories	—		364,562		456,879			—			821,441
Prepaid expenses and other current assets	13,647		24,214		225,412			(56,790		)	206,483
Total current assets	13,647		430,328		1,785,272			(56,790		)	2,172,457
Intercompany receivables, net	—		—		2,056,783			(2,056,783		)	—
Property, buildings and equipment, net	—		51,824		105,783			—			157,607
Intangible assets, net	—		3,417		389,945			—			393,362
Goodwill	—		244,648		1,476,066			—			1,720,714
Investments in affiliates	3,584,857		4,018,661		—			(7,603,518		)	—
Other assets	—		23,846		22,998			—			46,844
Total assets	$	3,598,504	$	4,772,724	$	5,836,847		$	(9,717,091	)	$	4,490,984

Accounts payable	$	—	$	381,795	$	302,926		$	—		$	684,721
Short-term debt	—		—		20,920			—			20,920
Other current liabilities	—		53,458		194,488			(56,790		)	191,156
Total current liabilities	—		435,253		518,334			(56,790		)	896,797
Intercompany payables, net	1,572,486		484,297		—			(2,056,783		)	—
Long-term debt	—		983,449		379,686			—			1,363,135
Other noncurrent liabilities	12,737		46,476		161,827			—			221,040
Total WESCO International stockholders’ equity	2,013,281		2,823,249		4,780,269			(7,603,518		)	2,013,281
Noncontrolling interests	—		—		(3,269		)	—			(3,269		)
Total liabilities and stockholders’ equity	$	3,598,504	$	4,772,724	$	5,836,847		$	(9,717,091	)	$	4,490,984



	Condensed Consolidating Balance Sheet
	December 31, 2015
	(In thousands)
	WESCO International, Inc.		WESCO Distribution, Inc.		Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Cash and cash equivalents	$	—	$	38,963	$	121,316		$	—		$	160,279
Trade accounts receivable, net	—		—		1,075,257			—			1,075,257
Inventories	—		376,641		433,426			—			810,067
Prepaid expenses and other current assets	15		47,290		173,596			(8,970		)	211,931
Total current assets	15		462,894		1,803,595			(8,970		)	2,257,534
Intercompany receivables, net	—		—		1,964,848			(1,964,848		)	—
Property, buildings and equipment, net	—		56,921		109,818			—			166,739
Intangible assets, net	—		4,072		399,577			—			403,649
Goodwill	—		255,251		1,426,411			—			1,681,662
Investments in affiliates	3,309,006		3,827,069		—			(7,136,075		)	—
Other assets	—		32,601		27,541			—			60,142
Total assets	$	3,309,021	$	4,638,808	$	5,731,790		$	(9,109,893	)	$	4,569,726

Accounts payable	$	—	$	414,524	$	300,995		$	—		$	715,519
Short-term debt	—		—		43,314			—			43,314
Other current liabilities	15,254		55,129		127,555			(8,970		)	188,968
Total current liabilities	15,254		469,653		471,864			(8,970		)	947,801
Intercompany payables, net	1,320,240		644,608		—			(1,964,848		)	—
Long-term debt	177,753		737,490		523,819			—			1,439,062
Other noncurrent liabilities	19,102		216,515		173,375			—			408,992
Total WESCO International stockholders’ equity	1,776,672		2,570,542		4,565,533			(7,136,075		)	1,776,672
Noncontrolling interests	—		—		(2,801		)	—			(2,801		)
Total liabilities and stockholders’ equity	$	3,309,021	$	4,638,808	$	5,731,790		$	(9,109,893	)	$	4,569,726

Condensed Income Statement [Table Text Block]



	Condensed Consolidating Statement of Income and Comprehensive Income
	Year ended December 31, 2016
	(In thousands)
	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—		$	3,306,265		$	4,134,508		$	(104,756	)	$	7,336,017
Cost of goods sold (excluding depreciation and	—			2,651,409			3,341,161			(104,756		)	5,887,814
amortization)
Selling, general and administrative expenses	61			477,437			571,788			—			1,049,286
Depreciation and amortization	—			20,226			46,632			—			66,858
Results of affiliates’ operations	240,571			155,814			—			(396,385		)	—
Interest expense (income), net	17,555			87,824			(28,804		)	—			76,575
Loss on debt redemption	123,933			—			—			—			123,933
Provision for income taxes	(2,098		)	8,263			24,266			—			30,431
Net income	101,120			216,920			179,465			(396,385		)	101,120
Less: Net loss attributable to noncontrolling interests	—			—			(468		)	—			(468		)
Net income attributable to WESCO International	$	101,120		$	216,920		$	179,933		$	(396,385	)	$	101,588
Other comprehensive income (loss):
Foreign currency translation adjustment	38,275			38,275			38,275			(76,550		)	38,275
Post retirement benefit plan adjustment	(2,485		)	(2,485		)	(2,485		)	4,970			(2,485		)
Comprehensive income attributable to WESCO International	$	136,910		$	252,710		$	215,723		$	(467,965	)	$	137,378



	Condensed Consolidating Statement of Income and Comprehensive Income (Loss)
	Year ended December 31, 2015
	(In thousands)
	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—		$	3,456,883		$	4,177,383		$	(115,779	)	$	7,518,487
Cost of goods sold (excluding depreciation and	—			2,784,413			3,356,192			(115,779		)	6,024,826
amortization)
Selling, general and administrative expenses	26			611,549			443,376			—			1,054,951
Depreciation and amortization	—			19,703			45,265			—			64,968
Results of affiliates’ operations	225,370			219,619			—			(444,989		)	—
Interest expense (income), net	24,910			63,261			(18,339		)	—			69,832
Provision for income taxes	(7,939		)	(6,929		)	110,405			—			95,537
Net income	208,373			204,505			240,484			(444,989		)	208,373
Less: Net loss attributable to noncontrolling interests	—			—			(2,314		)	—			(2,314		)
Net income attributable to WESCO International	$	208,373		$	204,505		$	242,798		$	(444,989	)	$	210,687
Other comprehensive income (loss):
Foreign currency translation adjustment	(225,795		)	(225,795		)	(225,795		)	451,590			(225,795		)
Post retirement benefit plan adjustment	4,532			4,532			4,532			(9,064		)	4,532
Comprehensive (loss) income attributable to WESCO International	$	(12,890	)	$	(16,758	)	$	21,535		$	(2,463	)	$	(10,576	)



	Condensed Consolidating Statement of Income and Comprehensive Income
	Year ended December 31, 2014
	(In thousands)
	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—		$	3,557,839		$	4,446,139		$	(114,352	)	$	7,889,626
Cost of goods sold (excluding depreciation and	—			2,848,413			3,544,523			(114,352		)	6,278,584
amortization)
Selling, general and administrative expenses	9			557,596			519,203			—			1,076,808
Depreciation and amortization	—			19,084			48,933			—			68,017
Results of affiliates’ operations	292,845			231,174			—			(524,019		)	—
Interest expense (income), net	24,472			74,653			(17,061		)	—			82,064
Provision for income taxes	(7,072		)	16,446			99,342			—			108,716
Net income	$	275,436		$	272,821		$	251,199		$	(524,019	)	$	275,437
Less: Net loss attributable to noncontrolling interests	—			—			(469		)	—			(469		)
Net income attributable to WESCO International	$	275,436		$	272,821		$	251,668		$	(524,019	)	$	275,906
Other comprehensive income (loss):
Foreign currency translation adjustment	(120,293		)	(120,293		)	(120,293		)	240,586			(120,293		)
Post retirement benefit plan adjustment	(5,056		)	(5,056		)	(5,056		)	10,112			(5,056		)
Comprehensive income attributable to WESCO International	$	150,087		$	147,472		$	126,319		$	(273,321	)	$	150,557

Condensed Cash Flow Statement [Table Text Block]



	Condensed Consolidating Statement of Cash Flows
	Year ended December 31, 2016
	(In thousands)
	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net cash provided by (used in) operating activities	$	95,388		$	(243,476	)	$	448,323		$	—		$	300,235
Investing activities:
Capital expenditures	—			(12,482		)	(5,475		)	—			(17,957		)
Acquisition payments, net of cash acquired	—			(50,890		)	—			—			(50,890		)
Proceeds from sale of assets	—			—			8,361			—			8,361
Dividends received from subsidiaries	—			82,912			—			(82,912		)	—
Advances to subsidiaries and other	—			(297,259		)	(337,344		)	624,603			(10,000		)
Net cash used in investing activities	—			(277,719		)	(334,458		)	541,691			(70,486		)
Financing activities:
Proceeds from issuance of debt	252,246			1,566,864			672,345			(297,259		)	2,194,196
Repayments of debt	(344,804		)	(1,030,520		)	(752,401		)	(327,344		)	(2,455,069		)
Equity activities	(2,830		)	—			—			—			(2,830		)
Dividends paid by subsidiaries	—			—			(82,912		)	82,912			—
Other	—			(12,560		)	—			—			(12,560		)
Net cash (used in) provided by financing activities	(95,388		)	523,784			(162,968		)	(541,691		)	(276,263		)
Effect of exchange rate changes on cash and cash equivalents	—			—			(3,634		)	—			(3,634		)
Net change in cash and cash equivalents	—			2,589			(52,737		)	—			(50,148		)
Cash and cash equivalents at the beginning of period	—			38,963			121,316			—			160,279
Cash and cash equivalents at the end of period	$	—		$	41,552		$	68,579		$	—		$	110,131



	Condensed Consolidating Statement of Cash Flows
	Year ended December 31, 2015
	(In thousands)
	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net cash provided by operating activities	$	3,531		$	214,037		$	65,481		$	—		$	283,049
Investing activities:
Capital expenditures	—			(15,266		)	(6,392		)	—			(21,658		)
Acquisition payments, net of cash acquired	—			(151,595		)	—			—			(151,595		)
Proceeds from sale of assets	—			—			3,023			—			3,023
Dividends received from subsidiaries	—			114,101			—			(114,101		)	—
Advances to subsidiaries and other	—			(197,345		)	17,461			179,884			—
Net cash (used in) provided by investing activities	—			(250,105		)	14,092			65,783			(170,230		)
Financing activities:
Proceeds from issuance of debt	150,705			1,224,596			452,655			(197,345		)	1,630,611
Repayments of debt	—			(1,175,056		)	(379,578		)	17,461			(1,537,173		)
Equity activities	(154,236		)	—			—			—			(154,236		)
Dividends paid by subsidiaries	—			—			(114,101		)	114,101			—
Other	—			(7,017		)	—			—			(7,017		)
Net cash provided by (used in) financing activities	(3,531		)	42,523			(41,024		)	(65,783		)	(67,815		)
Effect of exchange rate changes on cash and cash equivalents	—			—			(13,044		)	—			(13,044		)
Net change in cash and cash equivalents	—			6,455			25,505			—			31,960
Cash and cash equivalents at the beginning of period	—			32,508			95,811			—			128,319
Cash and cash equivalents at the end of period	$	—		$	38,963		$	121,316		$	—		$	160,279



	Condensed Consolidating Statement of Cash Flows
	Year ended December 31, 2014
	(In thousands)
	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net cash provided by operating activities	$	820		$	51,738		$	198,598		$	—		$	251,156
Investing activities:
Capital expenditures	—			(13,717		)	(6,831		)	—			(20,548		)
Acquisition payments, net of cash acquired	—			(42,226		)	(96,404		)	—			(138,630		)
Proceeds from sale of assets	—			—			14,991			—			14,991
Dividends received from subsidiaries	—			71,381			—			(71,381		)	—
Advances to subsidiaries and other	—			(53,779		)	17,461			36,318			—
Net cash used in investing activities	—			(38,341		)	(70,783		)	(35,063		)	(144,187		)
Financing activities:
Proceeds from issuance of debt	6,517			798,315			495,493			(60,437		)	1,239,888
Repayments of debt	(6,658		)	(807,776		)	(541,080		)	24,119			(1,331,395		)
Equity activities	(679		)	—			—			—			(679		)
Dividends paid by subsidiaries	—			—			(71,381		)	71,381			—
Other	—			(3,123		)	(181		)	—			(3,304		)
Net cash used in financing activities	(820		)	(12,584		)	(117,149		)	35,063			(95,490		)
Effect of exchange rate changes on cash and cash equivalents	—			—			(6,885		)	—			(6,885		)
Net change in cash and cash equivalents	—			813			3,781			—			4,594
Cash and cash equivalents at the beginning of period	—			31,695			92,030			—			123,725
Cash and cash equivalents at the end of period	$	—		$	32,508		$	95,811		$	—		$	128,319