EMPLOYEE BENEFIT PLANS	9 Months Ended
EMPLOYEE BENEFIT PLANS	Sep. 30, 2012
Compensation and Retirement Disclosure [Abstract]
EMPLOYEE BENEFIT PLANS	EMPLOYEE BENEFIT PLANS A majority of WESCO’s employees are covered by defined contribution retirement savings plans for their services rendered subsequent to WESCO’s formation. WESCO also offers a deferred compensation plan for select individuals. For U.S. participants, WESCO will make contributions in an amount equal to 50% of the participant’s total monthly contributions up to a maximum of 6% of eligible compensation. For Canadian participants, WESCO will make contributions in an amount ranging from 1% to 7% of the participant’s eligible compensation based on years of continuous service. In addition, employer contributions may be made at the discretion of the Board of Directors. For the nine months ended September 30, 2012 and 2011, WESCO incurred charges of $24.2 million and $19.5 million, respectively, for all such plans. Contributions are made in cash to defined contribution retirement savings plans. The deferred compensation plan is an unfunded plan. Employees have the option to transfer balances allocated to their accounts into any of the available investment options, including WESCO common stock.

The entire disclosure for pension and other postretirement benefits.

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