EARNINGS PER SHARE (Tables)

9 Months Ended

Sep. 30, 2012

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The following table sets forth the details of basic and diluted earnings per share:

	Three Months Ended
	September 30,
	2012		2011
Net income attributable to WESCO International, Inc.	$	63,415	$	53,890
Weighted average common shares outstanding used in computing basic earnings per share	43,705		43,289
Common shares issuable upon exercise of dilutive equity awards	1,032		976
Common shares issuable from contingently convertible debentures (see below for basis of calculation)	6,036		4,206
Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	50,773		48,471
Earnings per share attributable to WESCO International, Inc.
Basic	$	1.45	$	1.24
Diluted	$	1.25	$	1.11

	Nine Months Ended
	September 30,
	2012		2011
Net income attributable to WESCO International, Inc.	$	175,267	$	141,402
Weighted average common shares outstanding used in computing basic earnings per share	43,596		43,181
Common shares issuable upon exercise of dilutive equity awards	1,199		1,202
Common shares issuable from contingently convertible debentures (see below for basis of calculation)	6,262		5,400
Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	51,057		49,783
Earnings per share attributable to WESCO International, Inc.
Basic	$	4.02	$	3.27
Diluted	$	3.43	$	2.84