The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

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The cash outflow for loan and debt issuance costs.

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Debt (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Debt Instrument [Line Items]
Debt Instrument, Issuance Date			Jun. 15, 2016
Debt Instrument, Maturity Date			Jun. 15, 2024
Payments of Financing Costs			$ 6,000
Debt Instrument, Redemption, Description			At any time on or after June 15, 2019, WESCO Distribution may redeem all or a part of the 2024 Notes. Between June 15, 2019 and June 14, 2020, WESCO Distribution may redeem all or a part of the 2024 Notes at a redemption price equal to 104.031% of the principal amount. Between June 15, 2020 and June 14, 2021, WESCO Distribution may redeem all or a part of the 2024 Notes at a redemption price equal to 102.688% of the principal amount. Between June 15, 2021 and June 14, 2022, WESCO Distribution may redeem all or a part of the 2024 Notes at a redemption price equal to 101.344% of the principal amount. On and after June 15, 2022, WESCO Distribution may redeem all or a part of the 2024 Notes at a redemption price equal to 100% of the principal amount.
Debt Instrument, Redemption Price, Percentage			101.00%
Debt Instrument, Call Date, Earliest			Sep. 15, 2016
Repayments of Convertible Debt			$ (344,800)
Debt Instrument, Convertible, Terms of Conversion Feature			Holders who surrendered the 2029 Debentures for conversion received 18 shares of WESCO stock for each $1,000 principal amount of 2029 Debentures converted.
Debt Conversion, Converted Instrument, Shares Issued			6,267,688
Gain (Loss) on Extinguishment of Debt	$ (123,933)	$ 0	$ (123,933)	$ 0
Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 350,000		$ 350,000
Debt Instrument, Interest Rate, Stated Percentage	5.375%		5.375%