WESCO International (WCC) 10-Q 29 Oct 13 2013 Q3 Quarterly report Financial data

DOCUMENT_AND_ENTITY_INFORMATIO

DOCUMENT AND ENTITY INFORMATION Document	9 Months Ended
	Sep. 30, 2013	Oct. 28, 2013
Entity [Abstract]
Entity Registrant Name	WESCO INTERNATIONAL INC.
Entity Central Index Key	929008
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	30-Sep-13
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		44,196,606

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current Assets:
Cash and cash equivalents	$98,575	$86,099
Trade accounts receivable, net of allowance for doubtful accounts of $19,968 and $17,242 in 2013 and 2012, respectively	1,116,007	1,036,235
Other accounts receivable	120,587	89,801
Inventories, net	795,917	793,974
Current deferred income taxes	27,603	42,151
Prepaid expenses and other current assets	59,981	53,577
Total current assets	2,218,670	2,101,837
Property, buildings and equipment, net of accumulated depreciation of $211,193 and $199,115 in 2013 and 2012, respectively	201,905	210,723
Intangible assets, net	457,621	496,761
Goodwill	1,762,331	1,777,797
Other assets	38,944	42,511
Total assets	4,679,471	4,629,629
Current Liabilities:
Accounts payable	754,013	706,580
Accrued payroll and benefit costs	61,697	86,375
Short-term debt	32,428	30,136
Current portion of long-term debt	9,581	9,623
Current deferred income taxes	680	1,018
Other current liabilities	178,412	174,263
Total current liabilities	1,036,811	1,007,995
Long-term debt, net of discount of $181,311 and $183,644 in 2013 and 2012, respectively	1,535,464	1,695,413
Other noncurrent liabilities	52,169	72,060
Deferred income taxes	316,702	300,470
Total liabilities	2,941,146	3,075,938
Commitments and Contingencies
Stockholders' Equity:
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding	0	0
Additional capital	1,078,817	1,065,550
Retained earnings	1,310,393	1,092,719
Treasury stock, at cost; 18,167,744 and 18,102,528 shares in 2013 and 2012, respectively	-607,273	-604,050
Accumulated other comprehensive income	-44,255	-1,044
Total WESCO International stockholders' equity	1,738,325	1,553,691
Noncontrolling interest	20	-106
Total stockholders' equity	1,738,305	1,553,797
Total liabilities and stockholders' equity	4,679,471	4,629,629
Common Stock [Member]
Stockholders' Equity:
Common stock	580	579
Common Class B [Member]
Stockholders' Equity:
Common stock	$43	$43

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parentheticals) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Allowance for doubtful accounts	$19,968	$17,242
Accumulated depreciation	211,193	199,115
Debt discount	$180,309	$183,644
Preferred stock, par value (in dollars per share)	$0.01	$0.01
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Treasury stock, shares (in shares)	0	0
Common Stock [Member]
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized (in shares)	210,000,000	210,000,000
Common stock, shares, issued (in shares)	58,024,424	57,824,548
Common stock, shares outstanding (in shares)	44,196,111	44,061,451
Common Class B [Member]
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares, issued (in shares)	4,339,431	4,339,431
Common stock, shares outstanding (in shares)	0	0

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]
Net sales	$1,931,260	$1,656,186	$5,633,271	$4,934,938
Cost of goods sold	1,535,609	1,317,432	4,463,991	3,940,762
Selling, general and administrative expense	255,202	225,812	748,164	685,130
Depreciation and amortization	16,803	9,910	50,673	26,431
Income from operations	123,646	103,032	370,443	282,615
Interest expense, net	21,304	12,654	64,999	33,093
Loss on sale of Argentina business	2,315	0	2,315	0
Income before income taxes	100,027	90,378	303,129	249,522
Provision for income taxes	30,909	26,987	84,567	74,259
Net income	69,118	63,391	218,562	175,263
Net (loss) income attributable to noncontrolling interest	-44	-24	126	-4
Net income attributable to WESCO International, Inc.	69,162	63,415	218,436	175,267
Comprehensive Income:
Foreign currency translation adjustment	24,619	10,652	-43,211	14,297
Comprehensive income attributable to WESCO International, Inc.	$93,781	$74,067	$175,225	$189,564
Earnings per share attributable to WESCO International, Inc.
Basic (in dollars per share)	$1.57	$1.45	$4.95	$4.02
Diluted (in dollars per share)	$1.32	$1.25	$4.17	$3.43

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating Activities:
Net income	$218,562	$175,263
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	50,673	26,431
Share-based Compensation	12,534	11,722
Deferred income taxes	36,486	21,934
Other operating activities, net	2,485	-4,303
Changes in assets and liabilities
Trade receivables, net	-91,301	-60,633
Other accounts receivable	-32,580	-3,384
Inventories, net	-11,743	-16,028
Prepaid expenses and other current assets	-5,881	-2,281
Accounts payable	50,146	38,540
Accrued payroll and benefit costs	-24,851	-15,403
Accrued income taxes	892	3,954
Other current and noncurrent liabilities	-25,753	13,871
Net cash provided by operating activities	179,669	189,683
Investing Activities:
Capital expenditures	-20,472	-19,469
Acquisition payments, net of cash acquired	0	-201,123
Proceeds from sale of assets	10,481	51
Other investing activities	-1,205	0
Net cash used in investing activities	-11,196	-220,541
Financing Activities:
Proceeds from issuance of short-term debt	42,972	21,388
Repayments of short-term debt	-33,808	-2,129
Proceeds from issuance of long-term debt	759,470	740,450
Repayments of Long-term Debt	-915,562	-691,202
Increase (decrease) in bank overdrafts	-404	10,192
Other financing activities, net	-7,188	-4,308
Net cash used in financing activities	-154,520	74,391
Effect of exchange rate on cash and cash equivalents	-1,477	235
Net change in cash and cash equivalents	12,476	43,768
Cash and cash equivalents at the beginning of period	86,099	63,869
Cash and cash equivalents at the end of period	$98,575	$107,637

ORGANIZATION

ORGANIZATION	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION	ORGANIZATION
	WESCO International, Inc. and its subsidiaries (collectively, “WESCO” or the "Company"), headquartered in Pittsburgh, Pennsylvania, is a full-line distributor of electrical, industrial and communications maintenance, repair and operating (“MRO”) and original equipment manufactures (“OEM”) products, construction materials, and advanced supply chain management and logistics services used primarily in the industrial, construction, utility and commercial, institutional and government markets. We serve over 65,000 active customers globally, through approximately 475 full service branches and nine distribution centers located primarily in the United States, Canada and Mexico, with offices in 15 additional countries.

ACCOUNTING_POLICIES

ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]
ACCOUNTING POLICIES	ACCOUNTING POLICIES
	Basis of Presentation
	The unaudited condensed consolidated financial statements of WESCO have been prepared in accordance with Rule 10-01 of Regulation S-X of the Securities and Exchange Commission (the “SEC”). The unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in WESCO’s 2012 Annual Report on Form 10-K filed with the SEC. The December 31, 2012 condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by accounting principles generally accepted in the United States.
	The unaudited condensed consolidated balance sheet as of September 30, 2013, the unaudited condensed consolidated statements of income and comprehensive income for the three and nine months ended September 30, 2013 and 2012, respectively, and the unaudited condensed consolidated statements of cash flows for the nine months ended September 30, 2013 and 2012, respectively, in the opinion of management, have been prepared on the same basis as the audited consolidated financial statements and include all adjustments necessary for the fair statement of the results of the interim periods. All adjustments reflected in the unaudited condensed consolidated financial statements are of a normal recurring nature unless indicated. Results for the interim periods presented are not necessarily indicative of the results to be expected for the full year.
	Reclassification
	Certain prior period amounts have been reclassified to conform with the current period's financial statement presentation.
	Fair Value of Financial Instruments
	The Company measures the fair value of financial assets and liabilities based on the guidance of ASC 820, "Fair Value Measurements and Disclosures," which defines fair value, establishes a framework for measuring fair value, and expands disclosures about fair value measurements.
	ASC 820 establishes a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. ASC 820 describes three levels of inputs that may be used to measure fair value:
	Level 1 inputs are quoted prices in active markets for identical assets or liabilities.
	Level 2 inputs include inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of assets or liabilities.
	Level 3 inputs are unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.
	At September 30, 2013, the carrying value of WESCO’s 6.0% Convertible Senior Debentures due 2029 (the "2029 Debentures") was $173.4 million and the fair value was approximately $948.5 million. At December 31, 2012, the carrying value of WESCO’s 2029 Debentures was $171.2 million and the fair value was approximately $853.7 million. The fair value of WESCO’s 2029 Debentures is based on quoted prices in active markets and is therefore classified as Level 1 within the valuation hierarchy. The reported carrying amounts of WESCO’s other debt instruments approximate their fair values and are classified as Level 2 within the valuation hierarchy. Other debt instruments included in Level 2 are valued using a market approach, utilizing interest rates and other relevant information generated by market transactions involving similar instruments.
	Recent Accounting Pronouncements
	In July 2012, the Financial Accounting Standards Board (the "FASB") issued updated guidance on the periodic testing of indefinite-lived intangible assets, other than goodwill, for impairment. This updated guidance allows companies the option to first assess qualitative factors to determine if it is more-likely-than-not that an indefinite-lived intangible asset might be impaired and whether it is necessary to perform the quantitative impairment test required under current accounting standards. This guidance is effective for annual and interim impairment tests performed for fiscal years beginning after September 15, 2012. WESCO adopted this guidance in 2013. Adoption of this guidance did not have a material impact on WESCO's financial position, results of operations or cash flows.
	In February 2013, the FASB issued updated guidance on the reporting of amounts reclassified from accumulated other comprehensive income. This updated guidance requires entities to present significant amounts reclassified from each component of accumulated other comprehensive income and the income statement line items affected by the reclassification. This guidance is effective for interim and annual periods beginning after December 15, 2012. WESCO adopted this guidance in 2013. Adoption of this guidance did not have a material impact on WESCO's financial position, results of operations or cash flows.
	In July 2013, the FASB issued updated guidance on the presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. This updated guidance requires entities to present unrecognized tax benefits, or a portion of unrecognized tax benefits, in the financial statements as a reduction to deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, with certain exceptions. This guidance is effective for interim and annual periods beginning after December 15, 2013. WESCO will adopt this guidance in 2014. Adoption of this guidance is not expected to have a material impact on WESCO's financial position, results of operations or cash flows.

ACQUISITIONS

ACQUISITIONS	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS
	On December 14, 2012, WESCO completed its acquisition of EECOL Electric Corporation (“EECOL”), a full-line distributor of electrical equipment, products and services with 57 locations across Canada and 20 in South America. The purchase price allocation has not been finalized. The following unaudited pro forma results of operations illustrate the effect of the EECOL acquisition on the Company's sales and net income for the three and nine months ended September 30, 2012. This summary of the unaudited pro forma results of operations is not necessarily indicative of what WESCO's results of operations would have been had EECOL been acquired on the dates indicated, nor does it purport to represent results of operations for any future periods.
		Three Months Ended				Nine Months Ended
		September 30, 2013		September 30, 2012		September 30, 2013		September 30, 2012
	(In millions, except per share data)			(Pro forma)				(Pro forma)
	Net sales	$	1,931.30	$	1,907.40	$	5,633.30	$	5,633.80
	Net income attributable to WESCO International, Inc.	69.2		83		218.4		208
	Earnings per common share:
	Basic	$	1.57	$	1.9	$	4.95	$	4.77
	Diluted	$	1.32	$	1.63	$	4.17	$	4.07

STOCKBASED_COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION
	WESCO’s stock-based employee compensation plans are comprised of stock options, stock-settled stock appreciation rights, restricted stock units and performance-based awards. Compensation cost for all stock-based awards is measured at fair value on the date of grant, and compensation cost is recognized, net of estimated forfeitures, over the service period for awards expected to vest. The fair value of stock options and stock-settled appreciation rights is determined using the Black-Scholes valuation model. The fair value of restricted stock units is determined by the grant-date closing price of WESCO’s common stock. The forfeiture assumption is based on WESCO’s historical employee behavior that is reviewed on an annual basis. No dividends are assumed.
	During the three and nine months ended September 30, 2013 and 2012, WESCO granted the following stock-settled stock appreciation rights, restricted stock units and performance-based awards at the following weighted average assumptions:
		Three Months Ended September 30,					Nine Months Ended September 30,
		2013			2012		2013		2012
	Stock-settled appreciation rights granted	900			850		252,473		257,932
	Restricted stock units granted	—			2,400		69,393		74,724
	Performance-based awards granted	—			—		48,058		46,804
	Risk free interest rate	1.6	%		0.6	%	0.9	%	0.9	%
	Expected life (in years)	5			5		5		5
	Expected volatility	48	%		50	%	50	%	50	%
	For the three and nine months ended September 30, 2013, the weighted average fair value per stock-settled appreciation right granted was $32.05 and $31.33, respectively. For the three and nine months ended September 30, 2012, the weighted average fair value per stock-settled appreciation right granted was $24.33 and $27.89, respectively. For the nine months ended September 30, 2013 and 2012, the weighted average fair value per restricted stock unit granted was $72.15 and $64.27, respectively. For the nine months ended September 30, 2013 and 2012, the weighted average fair value per performance-based award granted was $78.21 and $75.72, respectively.
	The following table sets forth a summary of stock options and stock-settled stock appreciation rights and related information for the nine months ended September 30, 2013:
		Awards			Weighted			Weighted		Aggregate
					Average			Average		Intrinsic
					Exercise			Remaining		Value
					Price			Contractual Term (In Years)		(In thousands)
	Outstanding at December 31, 2012	3,142,021			$	45.4
	Granted	252,473			72.17
	Exercised	(344,446	)		46.88
	Forfeited	(18,530	)		60.74
	Outstanding at September 30, 2013	3,031,518			47.37			5.3		$	88,397
	Exercisable at September 30, 2013	2,508,083			$	43.32		4.6		$	83,305
	The following table sets forth a summary of restricted stock units and related information for the nine months ended September 30, 2013:
		Awards			Weighted
					Average
					Fair
					Value
	Unvested at December 31, 2012	187,335			$	52.28
	Granted	69,393			72.15
	Vested	(65,705	)		33.63
	Forfeited	(5,333	)		60.11
	Unvested at September 30, 2013	185,690			$	66.08
	Performance shares are awards for which the vesting will occur based on market or performance conditions. The following table sets forth a summary of performance-based awards for the nine months ended September 30, 2013:
		Awards			Weighted
					Average
					Fair
					Value
	Unvested at December 31, 2012	46,500			$	75.72
	Granted	48,058			78.21
	Vested	—			—
	Forfeited	(2,074	)		76.66
	Unvested at September 30, 2013	92,484			$	76.98
	The performance-based awards in the table above include 46,242 shares in which vesting of the ultimate number of shares underlying such awards is dependent upon WESCO's total stockholder return in relation to the total stockholder return of a select group of peer companies over a three-year period. These awards are valued based upon a Monte Carlo simulation model, which is a valuation model that represents the characteristics of these grants. The probability of meeting the market criteria was considered when calculating the estimated fair market value on the date of grant. These awards are accounted for as awards with market conditions, in which compensation cost is recognized over the service period, regardless of whether the market conditions are achieved and the awards ultimately vest.
	The fair value of the performance shares granted during the nine months ended September 30, 2013 were estimated using the following weighted-average assumptions:
	Weighted Average Assumptions
	Grant date share price	$	72.15
	WESCO expected volatility	37.8		%
	Peer group median volatility	29.1		%
	Risk-free interest rate	0.38		%
	Correlation	116.8		%
	Vesting of the remaining 46,242 shares of performance-based awards in the table above is dependent upon the three-year average growth rate of WESCO's net income. These awards are valued based upon the grant-date closing price of WESCO's common stock. These awards are accounted for as awards with performance conditions, in which compensation cost is recognized over the performance period based upon WESCO's determination of whether it is probable that the performance targets will be achieved.
	WESCO recognized $3.7 million and $3.2 million of non-cash stock-based compensation expense, which is included in selling, general and administrative expenses, for the three months ended September 30, 2013 and 2012, respectively. WESCO recognized $12.5 million and $11.7 million of non-cash stock-based compensation expense, which is included in selling, general and administrative expenses, for the nine months ended September 30, 2013 and 2012, respectively. As of September 30, 2013, there was $20.8 million of total unrecognized compensation cost related to non-vested stock-based compensation arrangements for all awards previously made, of which approximately $3.6 million is expected to be recognized over the remainder of 2013, $10.9 million in 2014, $5.5 million in 2015 and $0.8 million in 2016.
	During the nine months ended September 30, 2013 and 2012, the total intrinsic value of awards exercised was $14.1 million and $22.4 million, respectively. The total amount of cash received from the exercise of options was less than $0.1 million for the nine months ended September 30, 2013 and $0.2 million for the nine months ended September 30, 2012. The tax benefit associated with the exercise of awards for the nine months ended September 30, 2013 and 2012 totaled $4.8 million and $5.4 million, respectively, and was recorded as an increase to additional capital.

EARNINGS_PER_SHARE

EARNINGS PER SHARE	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE
	Basic earnings per share are computed by dividing net income by the weighted average common shares outstanding during the periods. Diluted earnings per share are computed by dividing net income by the weighted average common shares and common share equivalents outstanding during the periods. The dilutive effect of common share equivalents is considered in the diluted earnings per share computation using the treasury stock method, which includes consideration of stock-based compensation and convertible debt.
	The following table sets forth the details of basic and diluted earnings per share:
		Three Months Ended
		September 30,
		2013		2012
	Net income attributable to WESCO International, Inc.	$	69,162	$	63,415
	Weighted average common shares outstanding used in computing basic earnings per share	44,180		43,705
	Common shares issuable upon exercise of dilutive equity awards	1,067		1,032
	Common shares issuable from contingently convertible debentures (see below for basis of calculation)	7,299		6,036
	Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	52,546		50,773
	Earnings per share attributable to WESCO International, Inc.
	Basic	$	1.57	$	1.45
	Diluted	$	1.32	$	1.25
		Nine Months Ended
		September 30,
		2013		2012
	Net income attributable to WESCO International, Inc.	$	218,436	$	175,267
	Weighted average common shares outstanding used in computing basic earnings per share	44,127		43,596
	Common shares issuable upon exercise of dilutive equity awards	1,088		1,199
	Common shares issuable from contingently convertible debentures (see below for basis of calculation)	7,214		6,262
	Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	52,429		51,057
	Earnings per share attributable to WESCO International, Inc.
	Basic	$	4.95	$	4.02
	Diluted	$	4.17	$	3.43
	For the three and nine months ended September 30, 2013, the computation of diluted earnings per share attributable to WESCO International, Inc. excluded 0.3 million and 0.5 million stock-settled stock appreciation rights at weighted average exercise prices of $71.81 per share and $65.29 per share, respectively. For the three and nine months ended September 30, 2012, the computation of diluted earnings per share attributable to WESCO International, Inc. excluded 1.0 million and 1.2 million, respectively, stock-settled stock appreciation rights at weighted average exercise prices of $62.88 per share and $64.12 per share, respectively. These amounts were excluded because their effect would have been antidilutive.
	Because of WESCO’s obligation to settle the par value of the 2029 Debentures in cash upon conversion, WESCO is required to include shares underlying the 2029 Debentures in its diluted weighted average shares outstanding when the average stock price per share for the period exceeds the conversion price of the respective debentures. Only the number of shares issuable under the treasury stock method of accounting for share dilution are included, which is based upon the amount by which the average stock price exceeds the conversion price. The conversion price of the 2029 Debentures is $28.87. Share dilution is limited to a maximum of 11,948,894 shares for the 2029 Debentures. For the three and nine months ended September 30, 2013, the effect of the 2029 Debentures on diluted earnings per share attributable to WESCO International, Inc. was a decrease of $0.21 and $0.66, respectively. For the three and nine months ended September 30, 2012, the effect of the 2029 Debentures on diluted earnings per share attributable to WESCO International, Inc. was a decrease of $0.17 and $0.48, respectively.

ACCOUNTS_RECEIVABLE_SECURITIZA

ACCOUNTS RECEIVABLE SECURITIZATION FACILITY (Notes) (Accounts Receivable Securitization Facility [Member])	9 Months Ended
	Sep. 30, 2013
Accounts Receivable Securitization Facility [Member]
Schedule of Line of Credit Facilities [Table Text Block]	ACCOUNTS RECEIVABLE SECURITIZATION FACILITY
	On September 20, 2013, WESCO Distribution, Inc. (“WESCO Distribution”) and its subsidiary WESCO Receivables Corp. entered into an amendment (the “Amendment”) of the Third Amended and Restated Receivables Purchase Agreement (the “Receivables Facility”). The Amendment increases the purchase limit under the Receivables Facility from $475 million to $500 million, with the opportunity to exercise an accordion feature which permits increases in the purchase limit of up to an additional $100 million, extends the term of the Receivables Facility to September 20, 2016, and adds and amends certain defined terms. The Amendment also reduces the interest rate spread and commitment fee from 1.10% to 0.95% and from 0.55% to 0.45%, respectively. Substantially all other provisions of the Receivables Facility remain unchanged.
	Under the Receivables Facility, WESCO sells, on a continuous basis, an undivided interest in all domestic accounts receivable to WESCO Receivables Corp., a wholly owned special purpose entity (the “SPE”). The SPE sells, without recourse, a senior undivided interest in the receivables to third-party conduits and financial institutions for cash while maintaining a subordinated undivided interest in the receivables, in the form of overcollateralization. WESCO has agreed to continue servicing the sold receivables for the third-party conduits and financial institutions at market rates; accordingly, no servicing asset or liability has been recorded.
	The consolidated balance sheets as of September 30, 2013 and December 31, 2012 reflect $500 million and $445 million, respectively, of accounts receivable balances legally sold to third parties, as well as borrowings for equal amounts. At September 30, 2013, the interest rate on borrowings under this facility was approximately 1.1%.

EMPLOYEE_BENEFIT_PLANS

EMPLOYEE BENEFIT PLANS	9 Months Ended
	Sep. 30, 2013
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, 2013 and 2012, WESCO incurred charges of $25.7 million and $24.2 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 in the defined contribution retirement savings plan and the deferred compensation plan into any of the available investment options. An investment option for employees in the defined contribution retirement savings plan is WESCO common stock.
	In connection with the December 14, 2012 acquisition of EECOL, the Company assumed a contributory defined benefit plan covering substantially all Canadian employees of EECOL and a Supplemental Executive Retirement Plan for certain executives of EECOL. The following table reflects the components of net periodic benefit costs for the Company's defined benefit plans for the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
		2013			2012		2013			2012
	Service cost	$	996		$	—	$	3,049		$	—
	Interest cost	1,117			—		3,422			—
	Expected return on plan assets	(1,173		)	—		(3,081		)	—
	Net periodic benefit cost	$	940		$	—	$	3,390		$	—
	In the third quarter of 2013, the Company made a $21.1 million non-recurring contribution to its defined benefit plan covering all Canadian EECOL employees, as required pursuant to the terms of the share purchase agreement by which the Company acquired EECOL in 2012. EECOL sellers facilitated this contribution by way of a direct reduction in the purchase price at the date of acquisition. During the three and nine months ended September 30, 2013, the Company made cash contributions of $22.1 million and $23.9 million, respectively, to its defined benefit plans.

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES
	As initially reported in our 2008 Annual Report on Form 10-K, WESCO is a defendant in a lawsuit filed in a state court in Indiana in which a customer, ArcelorMittal Indiana Harbor, Inc. (“AIH”), alleges that the Company sold defective products to AIH in 2004 that were supplied to the Company by others.  The lawsuit sought monetary damages in the amount of approximately $50 million.  On February 14, 2013, the jury returned a verdict in favor of AIH and awarded damages in the amount of approximately $36.1 million, and judgment was entered on the jury's verdict.  The Company disputes this outcome and filed a post-trial motion challenging the verdict alleging various errors that occurred during trial.  The Company received letters from its insurers confirming insurance coverage of the matter and recorded a receivable in the quarter ended March 31, 2013 in an amount equal to the previously recorded liability. AIH also filed a post-trial motion asking the court to award additional amounts to AIH, including prejudgment and post-judgment interest.  The Court denied the Company's post-trial motion on June 28, 2013 and granted in part AIH's motion, awarding prejudgment interest in the amount of $3.9 million and ordering post-judgment interest to accrue on the entire judgment at 8% per annum. In the quarter ended June 30, 2013, the Company received letters from its insurers confirming insurance coverage of all prejudgment and post-judgment interest related to the matter, and recorded a liability and a corresponding receivable in the amount of $4.7 million for all interest accrued in connection with this matter. Final judgment was entered by the court on July 16, 2013, and the Company is appealing the judgment. The Company has recorded an additional liability and a corresponding receivable in the amount of $0.8 million for post-judgment interest accrued in connection with this matter during the quarter ended September 30, 2013. The judgment may increase or decrease based on the outcome of the appellate proceedings that cannot be predicted with certainty.

INCOME_TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES
	The effective tax rate for the three months ended September 30, 2013 and 2012 was 30.9% and 29.9% respectively, and the effective rate for the nine months ended September 30, 2013 and 2012 was 27.9% and 29.8%, respectively. WESCO’s three and nine month effective tax rates are lower than the federal statutory rate of 35% primarily due to benefits resulting from the tax effect of intercompany financing and lower tax rates on foreign earnings, which are partially offset by nondeductible expenses and state taxes. The effective tax rate for the nine months ended September 30, 2013 reflects discrete tax expense totaling $0.3 million, primarily related to enacted state tax rate changes and changes in uncertain tax positions. The effective tax rate for the nine months ended September 30, 2012 included discrete tax benefits totaling $3.2 million, primarily related to state taxes and changes in uncertain tax positions.
	The total amount of unrecognized tax benefits were $23.2 million and $21.1 million as of September 30, 2013 and December 31, 2012, respectively. A related deferred tax asset in the amount of $28.0 million excluding interest has been recorded. If these tax benefits were recognized in the consolidated financial statements, the portion of these amounts that would reduce the Company’s effective tax rate would be $23.2 million and $21.2 million, respectively. This amount would be offset by the corresponding deferred tax asset discussed above.
	During the next twelve months, it is reasonably possible that the amount of unrecognized tax benefits will decrease by as much as $17.2 million ($15.6 million of which will be offset by the reversal of deferred tax assets) due to possible resolution of federal, state and/or foreign tax examinations and/or the expiration of statutes of limitations. Management does not expect this decrease to have an impact on the effective tax rate.
	WESCO records interest related to uncertain tax positions as a part of interest expense in the consolidated statement of income. Any penalties are recognized as part of income tax expense. There were no material penalties recorded during the three or nine months ended September 30, 2013 or 2012. As of September 30, 2013, and December 31, 2012, WESCO had an accrued liability of $8.4 million and $8.0 million, respectively, for interest related to uncertain tax positions.

OTHER_FINANCIAL_INFORMATION

OTHER FINANCIAL INFORMATION	9 Months Ended
	Sep. 30, 2013
Condensed Financial Information [Abstract]
OTHER FINANCIAL INFORMATION	OTHER FINANCIAL INFORMATION
	WESCO International, Inc. ("WESCO International") has outstanding $344.9 million in aggregate principal amount of 2029 Debentures. The 2029 Debentures are fully and unconditionally guaranteed by WESCO Distribution, Inc. ("WESCO Distribution"), a 100% owned subsidiary of WESCO International, on a senior subordinated basis to all existing and future senior indebtedness of WESCO Distribution.
	Condensed consolidating financial information for WESCO International, WESCO Distribution and the non-guarantor subsidiaries is as follows:
	WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
	CONDENSED CONSOLIDATING BALANCE SHEETS
	(unaudited)
		September 30, 2013
		(In thousands)
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Cash and cash equivalents	$	—		$	45,838		$	52,737		$	—		$	98,575
	Trade accounts receivable, net	—			—			1,116,007			—			1,116,007
	Inventories, net	—			347,319			448,598			—			795,917
	Other current assets	—			93,993			114,178			—			208,171
	Total current assets	—			487,150			1,731,520			—			2,218,670
	Intercompany receivables, net	—			—			1,829,020			(1,829,020		)	—
	Property, buildings and equipment, net	—			59,135			142,770			—			201,905
	Intangible assets, net	—			5,538			452,083			—			457,621
	Goodwill	—			246,125			1,516,206			—			1,762,331
	Investments in affiliates	3,107,052			3,705,286			—			(6,812,338		)	—
	Other noncurrent assets	4,431			15,591			18,922			—			38,944
	Total assets	$	3,111,483		$	4,518,825		$	5,690,521		$	(8,641,358	)	$	4,679,471
	Accounts payable	$	—		$	413,738		$	340,275		$	—		$	754,013
	Short-term debt	—			—			32,428			—			32,428
	Other current liabilities	998			123,014			126,358			—			250,370
	Total current liabilities	998			536,752			499,061			—			1,036,811
	Intercompany payables, net	1,170,739			658,281			—			(1,829,020		)	—
	Long-term debt	173,374			715,221			646,869			—			1,535,464
	Other noncurrent liabilities	28,067			202,545			138,259			—			368,871
	Total WESCO International Stockholders' Equity	1,738,305			2,406,026			4,406,312			(6,812,338		)	1,738,305
	Noncontrolling interest	—			—			20			—			20
	Total liabilities and stockholders’ equity	$	3,111,483		$	4,518,825		$	5,690,521		$	(8,641,358	)	$	4,679,471
	WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
	CONDENSED CONSOLIDATING BALANCE SHEETS
	(unaudited)
		December 31, 2012
		(In thousands)
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Cash and cash equivalents	$	—		$	52,275		$	33,824		$	—		$	86,099
	Trade accounts receivable, net	—			—			1,036,235			—			1,036,235
	Inventories, net	—			347,008			446,966			—			793,974
	Other current assets	—			66,107			118,404			1,018			185,529
	Total current assets	—			465,390			1,635,429			1,018			2,101,837
	Intercompany receivables, net	—			—			1,756,898			(1,756,898		)	—
	Property, buildings and equipment, net	—			58,523			152,200			—			210,723
	Intangible assets, net	—			6,153			490,608			—			496,761
	Goodwill	—			246,125			1,531,672			—			1,777,797
	Investments in affiliates	2,918,779			3,590,772			—			(6,509,551		)	—
	Other noncurrent assets	4,671			16,842			19,656			1,342			42,511
	Total assets	$	2,923,450		$	4,383,805		$	5,586,463		$	(8,264,089	)	$	4,629,629
	Accounts payable	$	—		$	401,016		$	305,564		$	—		$	706,580
	Short-term debt	—			—			30,136			—			30,136
	Other current liabilities	16,779			100,956			152,526			1,018			271,279
	Total current liabilities	16,779			501,972			488,226			1,018			1,007,995
	Intercompany payables, net	1,153,562			603,336			—			(1,756,898		)	—
	Long-term debt	171,213			847,761			676,439			—			1,695,413
	Other noncurrent liabilities	28,099			190,294			152,795			1,342			372,530
	Total WESCO International Stockholders' Equity	1,553,797			2,240,442			4,269,109			(6,509,551		)	1,553,797
	Noncontrolling interest	—			—			(106		)	—			(106		)
Total liabilities and stockholders’ equity	$	2,923,450		$	4,383,805		$	5,586,463		$	(8,264,089	)	$	4,629,629
WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENTS OF INCOME AND COMPREHENSIVE INCOME
(unaudited)
	Three Months Ended September 30, 2013
	(In thousands)
	WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
	International,			Distribution,			Subsidiaries			and
	Inc.			Inc.						Eliminating
										Entries
Net sales	$	—		$	878,851		$	1,082,585		$	(30,176	)	$	1,931,260
Cost of goods sold	—			698,965			866,820			(30,176		)	1,535,609
Selling, general and administrative expenses	19			129,518			125,665			—			255,202
Depreciation and amortization	—			4,668			12,135			—			16,803
Results of affiliates’ operations	73,241			58,574			—			(131,815		)	—
Interest expense, net	5,944			18,823			(3,463		)	—			21,304
Loss on sale of Argentina business	—			—			2,315			—			2,315
Provision for income taxes	(1,840		)	19,856			12,893			—			30,909
Net income (loss)	69,118			65,595			66,220			(131,815		)	69,118
Less: Net income attributable to noncontrolling interest	—			—			(44		)	—			(44		)
Net income (loss) attributable to WESCO International, Inc.	$	69,118		$	65,595		$	66,264		$	(131,815	)	$	69,162
Comprehensive income:
Foreign currency translation adjustment	24,619			24,619			24,619			(49,238		)	24,619
Comprehensive income attributable to WESCO International, Inc.	$	93,737		$	90,214		$	90,883		$	(181,053	)	$	93,781
	Three Months Ended September 30, 2012
	(In thousands)
	WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
	International,			Distribution,			Subsidiaries			and
	Inc.			Inc.						Eliminating
										Entries
Net sales	$	—		$	868,289		$	818,213		$	(30,316	)	$	1,656,186
Cost of goods sold	—			689,462			658,286			(30,316		)	1,317,432
Selling, general and administrative expenses	25			121,067			104,720			—			225,812
Depreciation and amortization	—			3,979			5,931			—			9,910
Results of affiliates’ operations	68,055			34,887			—			(102,942		)	—
Interest expense, net	6,623			11,886			(5,855		)	—			12,654
Provision for income taxes	(1,984		)	16,248			12,723			—			26,987
Net income (loss)	63,391			60,534			42,408			(102,942		)	63,391
Less: Net income attributable to noncontrolling interest	—			—			(24		)	—			(24		)
Net income (loss) attributable to WESCO International, Inc.	$	63,391		$	60,534		$	42,432		$	(102,942	)	$	63,415
Comprehensive income:
Foreign currency translation adjustment	10,652			10,652			10,652			(21,304		)	10,652
Comprehensive income attributable to WESCO International, Inc.	$	74,043		$	71,186		$	53,084		$	(124,246	)	$	74,067
WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENTS OF INCOME AND COMPREHENSIVE INCOME
(unaudited)
	Nine Months Ended September 30, 2013
	(In thousands)
	WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
	International,			Distribution,			Subsidiaries			and
	Inc.			Inc.						Eliminating
										Entries
Net sales	$	—		$	2,572,693		$	3,154,350		$	(93,772	)	$	5,633,271
Cost of goods sold	—			2,047,937			2,509,826			(93,772		)	4,463,991
Selling, general and administrative expenses	24			368,853			379,287			—			748,164
Depreciation and amortization	—			13,551			37,122			—			50,673
Results of affiliates’ operations	231,481			157,726			—			(389,207		)	—
Interest expense, net	17,893			56,667			(9,561		)	—			64,999
Loss on sale of Argentina business	—			—			2,315			—			2,315
Provision for income taxes	(4,998		)	34,617			54,948			—			84,567
Net income (loss)	218,562			208,794			180,413			(389,207		)	218,562
Less: Net income attributable to noncontrolling interest	—			—			126			—			126
Net income (loss) attributable to WESCO International, Inc.	$	218,562		$	208,794		$	180,287		$	(389,207	)	$	218,436
Comprehensive income:
Foreign currency translation adjustment	(43,211		)	(43,211		)	(43,211		)	86,422			(43,211		)
Comprehensive income attributable to WESCO International, Inc.	$	175,351		$	165,583		$	137,076		$	(302,785	)	$	175,225
	Nine Months Ended September 30, 2012
	(In thousands)
	WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
	International,			Distribution,			Subsidiaries			and
	Inc.			Inc.						Eliminating
										Entries
Net sales	$	—		$	2,602,688		$	2,432,239		$	(99,989	)	$	4,934,938
Cost of goods sold	—			2,074,165			1,966,586			(99,989		)	3,940,762
Selling, general and administrative expenses	49			413,540			271,541			—			685,130
Depreciation and amortization	—			11,232			15,199			—			26,431
Results of affiliates’ operations	187,903			122,064			—			(309,967		)	—
Interest expense, net	17,944			32,200			(17,051		)	—			33,093
Provision for income taxes	(5,353		)	27,739			51,873			—			74,259
Net income (loss)	175,263			165,876			144,091			(309,967		)	175,263
Less: Net income attributable to noncontrolling interest	—			—			(4		)	—			(4		)
Net income (loss) attributable to WESCO International, Inc.	$	175,263		$	165,876		$	144,095		$	(309,967	)	$	175,267
Comprehensive income:
Foreign currency translation adjustment	14,297			14,297			14,297			(28,594		)	14,297
Comprehensive income attributable to WESCO International, Inc.	$	189,560		$	180,173		$	158,392		$	(338,561	)	$	189,564
WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS
(unaudited)
	Nine Months Ended September 30, 2013
	(In thousands)
	WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
	International,			Distribution,			Subsidiaries			and Eliminating
	Inc.			Inc.						Entries
Net cash (used) provided by operating activities	$	(14,515	)	$	163,190		$	30,994		$	—		$	179,669
Investing activities:
Capital expenditures	—			(16,421		)	(4,051		)	—			(20,472		)
Acquisition payments	—			—			—			—			—
Proceeds from sale of assets	—			—			10,481			—			10,481
Other				(17,176		)	(1,205		)	17,176			(1,205		)
Net cash (used) provided by investing activities	—			(33,597		)	5,225			17,176			(11,196		)
Financing activities:
Borrowings	17,176			508,213			294,229			(17,176		)	802,442
Repayments				(640,713		)	(308,657		)				(949,370		)
Other	(2,661		)	(3,530		)	(1,401		)	—			(7,592		)
Net cash provided (used) by financing activities	14,515			(136,030		)	(15,829		)	(17,176		)	(154,520		)
Effect of exchange rate changes on cash and cash equivalents	—			—			(1,477		)	—			(1,477		)
Net change in cash and cash equivalents	—			(6,437		)	18,913			—			12,476
Cash and cash equivalents at the beginning of year	—			52,275			33,824			—			86,099
Cash and cash equivalents at the end of period	$	—		$	45,838		$	52,737		$	—		$	98,575
WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS
(unaudited)
	Nine Months Ended September 30, 2012
	(In thousands)
	WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
	International,			Distribution,			Subsidiaries			and Eliminating
	Inc.			Inc.						Entries
Net cash (used) provided by operating activities	$	(3,020	)	$	272,123		$	(79,420	)	$	—		$	189,683
Investing activities:
Capital expenditures	—			(15,654		)	(3,815		)	—			(19,469		)
Acquisition payments	—			(142,483		)	(58,640		)	—			(201,123		)
Proceeds from sale of assets	—			51			—			—			51
Other	—			(64,129		)	—			64,129			—
Net cash used in investing activities	—			(222,215		)	(62,455		)	64,129			(220,541		)
Financing activities:
Borrowings	5,489			177,300			643,178			(64,129		)	761,838
Repayments	—			(204,300		)	(489,031		)	—			(693,331		)
Other	(2,469		)	8,353			—			—			5,884
Net cash provided (used) by financing activities	3,020			(18,647		)	154,147			(64,129		)	74,391
Effect of exchange rate changes on cash and cash equivalents	—			—			235			—			235
Net change in cash and cash equivalents	—			31,261			12,507			—			43,768
Cash and cash equivalents at the beginning of year	—			44,412			19,457			—			63,869
Cash and cash equivalents at the end of period	$	—		$	75,673		$	31,964		$	—		$	107,637
The Company revised its condensed consolidating balance sheet as of December 31, 2012 to include WESCO Finance Corporation ("WESCO Finance"), a subsidiary of WESCO International, as a non-guarantor subsidiary. Previously, WESCO Finance was included in the WESCO International column of the Company's condensed consolidating balance sheets. In doing so, the Company recorded the $480.2 million investment in WESCO Finance as an increase in investments in affiliates, with an offsetting increase in intercompany payables, net. The Company increased intercompany receivables, net by $679.9 million with a corresponding increase in stockholders' equity of non-guarantor subsidiaries to record WESCO Finance as a non-guarantor subsidiary. Additionally, the Company recorded the cumulative accrued interest payable of $198.1 million related to an intercompany loan between WESCO Distribution and WESCO Finance by adjusting the stockholders' equity of WESCO Distribution at December 31, 2012 with a corresponding increase in intercompany payables, net. The Company also decreased non-current liabilities of WESCO International by $1.6 million with a corresponding increase to intercompany payable, net at December 31, 2012. The Company made additional immaterial revisions related to other intercompany transactions in the condensed consolidating balance sheet at December 31, 2012.
The Company revised its condensed consolidating statements of income and comprehensive income for the three month and nine month periods ended September 30, 2012. The Company revised net sales related to intercompany sales eliminations by increasing net sales of non-guarantor subsidiaries by $2.0 million and decreasing net sales in consolidating and eliminated entries for the same amount for the three month period ending September 30, 2012. The Company revised interest expense related to intercompany borrowings increasing interest expense of WESCO International by $0.5 million and $0.5 million, increasing interest expense of WESCO Distribution by $8.2 million and $24.5 million and decreasing interest expense of non-guarantor subsidiaries by $8.7 million and $25.0 million for the three and nine month periods ending September 30, 2012. In addition, the Company revised its methodology for allocating income tax expense during interim reporting periods, resulting in a decrease in income tax expense of WESCO International by $2.0 million and $5.4 million, a decrease in income tax expense of WESCO Distribution by $8.4 million and $40.0 million and an increase in income tax expense of non-guarantor subsidiaries by $10.4 million and $45.4 million for the three and nine month periods ending September 30, 2012, respectively.
The Company revised its condensed statement of cash flows to present cash paid for acquisitions of $58.6 million for the nine months ended September 30, 2012 as intercompany loans to non-guarantor subsidiaries. These payments represent acquisitions made by the non-guarantor subsidiaries that were funded by WESCO Distribution. Such transactions have now been revised to reflect an investing cash outflow and a corresponding intercompany borrowing from WESCO Distribution as a financing cash inflow in the statement of cash flows of the non-guarantor subsidiaries. Additionally, the revised statements present proceeds from issuance of debt and repayments of debt along with properly classifying debt between WESCO Distribution (proceeds of $177.3 million and repayments of $204.3 million) and non-guarantor subsidiaries (proceeds of $643.2 million and repayments of $489.0 million). Lastly, the Company revised its condensed consolidating statement of cash flows to reflect a $5.5 million advance from WESCO Distribution to WESCO International.
The impact of the revisions noted above, which the Company has determined is not material to the consolidated financial statements taken as a whole, did not have any impact on the consolidated amounts previously reported, nor did they impact the Company's obligations under the 2029 Debentures. The prior period condensed consolidating financial statements will be similarly revised as the information is presented in the Company's annual Form 10-K filing for 2013 and first quarter Form 10-Q filing for 2014.

ACCOUNTING_POLICIES_Policies

ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
	The unaudited condensed consolidated financial statements of WESCO have been prepared in accordance with Rule 10-01 of Regulation S-X of the Securities and Exchange Commission (the “SEC”). The unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in WESCO’s 2012 Annual Report on Form 10-K filed with the SEC. The December 31, 2012 condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by accounting principles generally accepted in the United States.
	The unaudited condensed consolidated balance sheet as of September 30, 2013, the unaudited condensed consolidated statements of income and comprehensive income for the three and nine months ended September 30, 2013 and 2012, respectively, and the unaudited condensed consolidated statements of cash flows for the nine months ended September 30, 2013 and 2012, respectively, in the opinion of management, have been prepared on the same basis as the audited consolidated financial statements and include all adjustments necessary for the fair statement of the results of the interim periods. All adjustments reflected in the unaudited condensed consolidated financial statements are of a normal recurring nature unless indicated. Results for the interim periods presented are not necessarily indicative of the results to be expected for the full year.
Reclassification	Reclassification
	Certain prior period amounts have been reclassified to conform with the current period's financial statement presentation.
Fair Value of Financial Instruments	Fair Value of Financial Instruments
	The Company measures the fair value of financial assets and liabilities based on the guidance of ASC 820, "Fair Value Measurements and Disclosures," which defines fair value, establishes a framework for measuring fair value, and expands disclosures about fair value measurements.
	ASC 820 establishes a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. ASC 820 describes three levels of inputs that may be used to measure fair value:
	Level 1 inputs are quoted prices in active markets for identical assets or liabilities.
	Level 2 inputs include inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of assets or liabilities.
	Level 3 inputs are unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.
	At September 30, 2013, the carrying value of WESCO’s 6.0% Convertible Senior Debentures due 2029 (the "2029 Debentures") was $173.4 million and the fair value was approximately $948.5 million. At December 31, 2012, the carrying value of WESCO’s 2029 Debentures was $171.2 million and the fair value was approximately $853.7 million. The fair value of WESCO’s 2029 Debentures is based on quoted prices in active markets and is therefore classified as Level 1 within the valuation hierarchy. The reported carrying amounts of WESCO’s other debt instruments approximate their fair values and are classified as Level 2 within the valuation hierarchy. Other debt instruments included in Level 2 are valued using a market approach, utilizing interest rates and other relevant information generated by market transactions involving similar instruments.

ACQUISITIONS_Tables

ACQUISITIONS (Tables)	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]
Business Acquisition, Pro Forma Information [Table Text Block]	This summary of the unaudited pro forma results of operations is not necessarily indicative of what WESCO's results of operations would have been had EECOL been acquired on the dates indicated, nor does it purport to represent results of operations for any future periods.
		Three Months Ended				Nine Months Ended
		September 30, 2013		September 30, 2012		September 30, 2013		September 30, 2012
	(In millions, except per share data)			(Pro forma)				(Pro forma)
	Net sales	$	1,931.30	$	1,907.40	$	5,633.30	$	5,633.80
	Net income attributable to WESCO International, Inc.	69.2		83		218.4		208
	Earnings per common share:
	Basic	$	1.57	$	1.9	$	4.95	$	4.77
	Diluted	$	1.32	$	1.63	$	4.17	$	4.07

STOCKBASED_COMPENSATION_Tables

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	During the three and nine months ended September 30, 2013 and 2012, WESCO granted the following stock-settled stock appreciation rights, restricted stock units and performance-based awards at the following weighted average assumptions:
		Three Months Ended September 30,					Nine Months Ended September 30,
		2013			2012		2013		2012
	Stock-settled appreciation rights granted	900			850		252,473		257,932
	Restricted stock units granted	—			2,400		69,393		74,724
	Performance-based awards granted	—			—		48,058		46,804
	Risk free interest rate	1.6	%		0.6	%	0.9	%	0.9	%
	Expected life (in years)	5			5		5		5
	Expected volatility	48	%		50	%	50	%	50	%
Schedule of Share-based Compensation, Stock Options and Stock Appreciation Rights Award Activity [Table Text Block]	The following table sets forth a summary of stock options and stock-settled stock appreciation rights and related information for the nine months ended September 30, 2013:
		Awards			Weighted			Weighted		Aggregate
					Average			Average		Intrinsic
					Exercise			Remaining		Value
					Price			Contractual Term (In Years)		(In thousands)
	Outstanding at December 31, 2012	3,142,021			$	45.4
	Granted	252,473			72.17
	Exercised	(344,446	)		46.88
	Forfeited	(18,530	)		60.74
	Outstanding at September 30, 2013	3,031,518			47.37			5.3		$	88,397
	Exercisable at September 30, 2013	2,508,083			$	43.32		4.6		$	83,305
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]	The following table sets forth a summary of restricted stock units and related information for the nine months ended September 30, 2013:
		Awards			Weighted
					Average
					Fair
					Value
	Unvested at December 31, 2012	187,335			$	52.28
	Granted	69,393			72.15
	Vested	(65,705	)		33.63
	Forfeited	(5,333	)		60.11
	Unvested at September 30, 2013	185,690			$	66.08
Schedule of Nonvested Performance-based Units Activity [Table Text Block]	The following table sets forth a summary of performance-based awards for the nine months ended September 30, 2013:
		Awards			Weighted
					Average
					Fair
					Value
	Unvested at December 31, 2012	46,500			$	75.72
	Granted	48,058			78.21
	Vested	—			—
	Forfeited	(2,074	)		76.66
	Unvested at September 30, 2013	92,484			$	76.98
Schedule of Share-based Payment Award, Performance-based Awards, Valuation Assumptions [Table Text Block]	The fair value of the performance shares granted during the nine months ended September 30, 2013 were estimated using the following weighted-average assumptions:
	Weighted Average Assumptions
	Grant date share price	$	72.15
	WESCO expected volatility	37.8		%
	Peer group median volatility	29.1		%
	Risk-free interest rate	0.38		%
	Correlation	116.8		%

EARNINGS_PER_SHARE_Tables

EARNINGS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2013
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,
		2013		2012
	Net income attributable to WESCO International, Inc.	$	69,162	$	63,415
	Weighted average common shares outstanding used in computing basic earnings per share	44,180		43,705
	Common shares issuable upon exercise of dilutive equity awards	1,067		1,032
	Common shares issuable from contingently convertible debentures (see below for basis of calculation)	7,299		6,036
	Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	52,546		50,773
	Earnings per share attributable to WESCO International, Inc.
	Basic	$	1.57	$	1.45
	Diluted	$	1.32	$	1.25
		Nine Months Ended
		September 30,
		2013		2012
	Net income attributable to WESCO International, Inc.	$	218,436	$	175,267
	Weighted average common shares outstanding used in computing basic earnings per share	44,127		43,596
	Common shares issuable upon exercise of dilutive equity awards	1,088		1,199
	Common shares issuable from contingently convertible debentures (see below for basis of calculation)	7,214		6,262
	Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	52,429		51,057
	Earnings per share attributable to WESCO International, Inc.
	Basic	$	4.95	$	4.02
	Diluted	$	4.17	$	3.43

EMPLOYEE_BENEFIT_PLANS_Schedul

EMPLOYEE BENEFIT PLANS Schedule of Net Benefit Costs (Tables)	9 Months Ended
	Sep. 30, 2013
Postemployment Benefits [Abstract]
Schedule of Net Benefit Costs [Table Text Block]	The following table reflects the components of net periodic benefit costs for the Company's defined benefit plans for the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
		2013			2012		2013			2012
	Service cost	$	996		$	—	$	3,049		$	—
	Interest cost	1,117			—		3,422			—
	Expected return on plan assets	(1,173		)	—		(3,081		)	—
	Net periodic benefit cost	$	940		$	—	$	3,390		$	—

OTHER_FINANCIAL_INFORMATION_Ta

OTHER FINANCIAL INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2013
Condensed Financial Information [Abstract]
Condensed Financial Information Statements Of Financial Condition [Text Block]	Condensed consolidating financial information for WESCO International, WESCO Distribution and the non-guarantor subsidiaries is as follows:
	WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
	CONDENSED CONSOLIDATING BALANCE SHEETS
	(unaudited)
		September 30, 2013
		(In thousands)
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Cash and cash equivalents	$	—		$	45,838		$	52,737		$	—		$	98,575
	Trade accounts receivable, net	—			—			1,116,007			—			1,116,007
	Inventories, net	—			347,319			448,598			—			795,917
	Other current assets	—			93,993			114,178			—			208,171
	Total current assets	—			487,150			1,731,520			—			2,218,670
	Intercompany receivables, net	—			—			1,829,020			(1,829,020		)	—
	Property, buildings and equipment, net	—			59,135			142,770			—			201,905
	Intangible assets, net	—			5,538			452,083			—			457,621
	Goodwill	—			246,125			1,516,206			—			1,762,331
	Investments in affiliates	3,107,052			3,705,286			—			(6,812,338		)	—
	Other noncurrent assets	4,431			15,591			18,922			—			38,944
	Total assets	$	3,111,483		$	4,518,825		$	5,690,521		$	(8,641,358	)	$	4,679,471
	Accounts payable	$	—		$	413,738		$	340,275		$	—		$	754,013
	Short-term debt	—			—			32,428			—			32,428
	Other current liabilities	998			123,014			126,358			—			250,370
	Total current liabilities	998			536,752			499,061			—			1,036,811
	Intercompany payables, net	1,170,739			658,281			—			(1,829,020		)	—
	Long-term debt	173,374			715,221			646,869			—			1,535,464
	Other noncurrent liabilities	28,067			202,545			138,259			—			368,871
	Total WESCO International Stockholders' Equity	1,738,305			2,406,026			4,406,312			(6,812,338		)	1,738,305
	Noncontrolling interest	—			—			20			—			20
	Total liabilities and stockholders’ equity	$	3,111,483		$	4,518,825		$	5,690,521		$	(8,641,358	)	$	4,679,471
	WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
	CONDENSED CONSOLIDATING BALANCE SHEETS
	(unaudited)
		December 31, 2012
		(In thousands)
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Cash and cash equivalents	$	—		$	52,275		$	33,824		$	—		$	86,099
	Trade accounts receivable, net	—			—			1,036,235			—			1,036,235
	Inventories, net	—			347,008			446,966			—			793,974
	Other current assets	—			66,107			118,404			1,018			185,529
	Total current assets	—			465,390			1,635,429			1,018			2,101,837
	Intercompany receivables, net	—			—			1,756,898			(1,756,898		)	—
	Property, buildings and equipment, net	—			58,523			152,200			—			210,723
	Intangible assets, net	—			6,153			490,608			—			496,761
	Goodwill	—			246,125			1,531,672			—			1,777,797
	Investments in affiliates	2,918,779			3,590,772			—			(6,509,551		)	—
	Other noncurrent assets	4,671			16,842			19,656			1,342			42,511
	Total assets	$	2,923,450		$	4,383,805		$	5,586,463		$	(8,264,089	)	$	4,629,629
	Accounts payable	$	—		$	401,016		$	305,564		$	—		$	706,580
	Short-term debt	—			—			30,136			—			30,136
	Other current liabilities	16,779			100,956			152,526			1,018			271,279
	Total current liabilities	16,779			501,972			488,226			1,018			1,007,995
	Intercompany payables, net	1,153,562			603,336			—			(1,756,898		)	—
	Long-term debt	171,213			847,761			676,439			—			1,695,413
	Other noncurrent liabilities	28,099			190,294			152,795			1,342			372,530
	Total WESCO International Stockholders' Equity	1,553,797			2,240,442			4,269,109			(6,509,551		)	1,553,797
	Noncontrolling interest	—			—			(106		)	—			(106		)
	Total liabilities and stockholders’ equity	$	2,923,450		$	4,383,805		$	5,586,463		$	(8,264,089	)	$	4,629,629
Condensed Financial Information Statement Of Income [Text Block]
		Three Months Ended September 30, 2013
		(In thousands)
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Net sales	$	—		$	878,851		$	1,082,585		$	(30,176	)	$	1,931,260
	Cost of goods sold	—			698,965			866,820			(30,176		)	1,535,609
	Selling, general and administrative expenses	19			129,518			125,665			—			255,202
	Depreciation and amortization	—			4,668			12,135			—			16,803
	Results of affiliates’ operations	73,241			58,574			—			(131,815		)	—
	Interest expense, net	5,944			18,823			(3,463		)	—			21,304
	Loss on sale of Argentina business	—			—			2,315			—			2,315
	Provision for income taxes	(1,840		)	19,856			12,893			—			30,909
	Net income (loss)	69,118			65,595			66,220			(131,815		)	69,118
	Less: Net income attributable to noncontrolling interest	—			—			(44		)	—			(44		)
	Net income (loss) attributable to WESCO International, Inc.	$	69,118		$	65,595		$	66,264		$	(131,815	)	$	69,162
	Comprehensive income:
	Foreign currency translation adjustment	24,619			24,619			24,619			(49,238		)	24,619
	Comprehensive income attributable to WESCO International, Inc.	$	93,737		$	90,214		$	90,883		$	(181,053	)	$	93,781
		Three Months Ended September 30, 2012
		(In thousands)
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Net sales	$	—		$	868,289		$	818,213		$	(30,316	)	$	1,656,186
	Cost of goods sold	—			689,462			658,286			(30,316		)	1,317,432
	Selling, general and administrative expenses	25			121,067			104,720			—			225,812
	Depreciation and amortization	—			3,979			5,931			—			9,910
	Results of affiliates’ operations	68,055			34,887			—			(102,942		)	—
	Interest expense, net	6,623			11,886			(5,855		)	—			12,654
	Provision for income taxes	(1,984		)	16,248			12,723			—			26,987
	Net income (loss)	63,391			60,534			42,408			(102,942		)	63,391
	Less: Net income attributable to noncontrolling interest	—			—			(24		)	—			(24		)
	Net income (loss) attributable to WESCO International, Inc.	$	63,391		$	60,534		$	42,432		$	(102,942	)	$	63,415
	Comprehensive income:
	Foreign currency translation adjustment	10,652			10,652			10,652			(21,304		)	10,652
	Comprehensive income attributable to WESCO International, Inc.	$	74,043		$	71,186		$	53,084		$	(124,246	)	$	74,067
	WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENTS OF INCOME AND COMPREHENSIVE INCOME
	(unaudited)
		Nine Months Ended September 30, 2013
		(In thousands)
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Net sales	$	—		$	2,572,693		$	3,154,350		$	(93,772	)	$	5,633,271
	Cost of goods sold	—			2,047,937			2,509,826			(93,772		)	4,463,991
	Selling, general and administrative expenses	24			368,853			379,287			—			748,164
	Depreciation and amortization	—			13,551			37,122			—			50,673
	Results of affiliates’ operations	231,481			157,726			—			(389,207		)	—
	Interest expense, net	17,893			56,667			(9,561		)	—			64,999
	Loss on sale of Argentina business	—			—			2,315			—			2,315
	Provision for income taxes	(4,998		)	34,617			54,948			—			84,567
	Net income (loss)	218,562			208,794			180,413			(389,207		)	218,562
	Less: Net income attributable to noncontrolling interest	—			—			126			—			126
	Net income (loss) attributable to WESCO International, Inc.	$	218,562		$	208,794		$	180,287		$	(389,207	)	$	218,436
	Comprehensive income:
	Foreign currency translation adjustment	(43,211		)	(43,211		)	(43,211		)	86,422			(43,211		)
	Comprehensive income attributable to WESCO International, Inc.	$	175,351		$	165,583		$	137,076		$	(302,785	)	$	175,225
		Nine Months Ended September 30, 2012
	(In thousands)
	WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
	International,			Distribution,			Subsidiaries			and
	Inc.			Inc.						Eliminating
										Entries
Net sales	$	—		$	2,602,688		$	2,432,239		$	(99,989	)	$	4,934,938
Cost of goods sold	—			2,074,165			1,966,586			(99,989		)	3,940,762
Selling, general and administrative expenses	49			413,540			271,541			—			685,130
Depreciation and amortization	—			11,232			15,199			—			26,431
Results of affiliates’ operations	187,903			122,064			—			(309,967		)	—
Interest expense, net	17,944			32,200			(17,051		)	—			33,093
Provision for income taxes	(5,353		)	27,739			51,873			—			74,259
Net income (loss)	175,263			165,876			144,091			(309,967		)	175,263
Less: Net income attributable to noncontrolling interest	—			—			(4		)	—			(4		)
Net income (loss) attributable to WESCO International, Inc.	$	175,263		$	165,876		$	144,095		$	(309,967	)	$	175,267
Comprehensive income:
Foreign currency translation adjustment	14,297			14,297			14,297			(28,594		)	14,297
Comprehensive income attributable to WESCO International, Inc.	$	189,560		$	180,173		$	158,392		$	(338,561	)	$	189,564
Condensed Financial Information Statements Of Cash Flows [Text Block]
		Nine Months Ended September 30, 2013
		(In thousands)
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and Eliminating
		Inc.			Inc.						Entries
	Net cash (used) provided by operating activities	$	(14,515	)	$	163,190		$	30,994		$	—		$	179,669
	Investing activities:
	Capital expenditures	—			(16,421		)	(4,051		)	—			(20,472		)
	Acquisition payments	—			—			—			—			—
	Proceeds from sale of assets	—			—			10,481			—			10,481
	Other				(17,176		)	(1,205		)	17,176			(1,205		)
	Net cash (used) provided by investing activities	—			(33,597		)	5,225			17,176			(11,196		)
	Financing activities:
	Borrowings	17,176			508,213			294,229			(17,176		)	802,442
	Repayments				(640,713		)	(308,657		)				(949,370		)
	Other	(2,661		)	(3,530		)	(1,401		)	—			(7,592		)
	Net cash provided (used) by financing activities	14,515			(136,030		)	(15,829		)	(17,176		)	(154,520		)
	Effect of exchange rate changes on cash and cash equivalents	—			—			(1,477		)	—			(1,477		)
	Net change in cash and cash equivalents	—			(6,437		)	18,913			—			12,476
	Cash and cash equivalents at the beginning of year	—			52,275			33,824			—			86,099
	Cash and cash equivalents at the end of period	$	—		$	45,838		$	52,737		$	—		$	98,575
	WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS
	(unaudited)
		Nine Months Ended September 30, 2012
		(In thousands)
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and Eliminating
		Inc.			Inc.						Entries
	Net cash (used) provided by operating activities	$	(3,020	)	$	272,123		$	(79,420	)	$	—		$	189,683
	Investing activities:
	Capital expenditures	—			(15,654		)	(3,815		)	—			(19,469		)
	Acquisition payments	—			(142,483		)	(58,640		)	—			(201,123		)
	Proceeds from sale of assets	—			51			—			—			51
	Other	—			(64,129		)	—			64,129			—
	Net cash used in investing activities	—			(222,215		)	(62,455		)	64,129			(220,541		)
	Financing activities:
	Borrowings	5,489			177,300			643,178			(64,129		)	761,838
	Repayments	—			(204,300		)	(489,031		)	—			(693,331		)
	Other	(2,469		)	8,353			—			—			5,884
	Net cash provided (used) by financing activities	3,020			(18,647		)	154,147			(64,129		)	74,391
	Effect of exchange rate changes on cash and cash equivalents	—			—			235			—			235
	Net change in cash and cash equivalents	—			31,261			12,507			—			43,768
	Cash and cash equivalents at the beginning of year	—			44,412			19,457			—			63,869
	Cash and cash equivalents at the end of period	$	—		$	75,673		$	31,964		$	—		$	107,637

ORGANIZATION_Details

ORGANIZATION (Details)	9 Months Ended
	Sep. 30, 2013
	customers
	countries
	distribution_centers
	branches
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Active customers (in customers)	65,000
Full service branches (in branches)	475
Distribution centers (in distribution centers)	9
Additional countries (in countries)	15

ACCOUNTING_POLICIES_Details

ACCOUNTING POLICIES (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Accounting Policies [Abstract]
Fixed Rate Debt, Par Value	$173.40	$171.20
Fixed Rate Debt, Fair Value Disclosures	$948.50	$853.70

ACQUISITIONS_ACQUISITIONS_Deta

ACQUISITIONS - ACQUISITIONS (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Business Combination, Pro Forma Information [Abstract]
Revenue, Net	$1,931,260,000	$1,656,186,000	$5,633,271,000	$4,934,938,000
Net Sales			1,907,400,000	5,633,800,000
Net Income (Loss) Attributable to Parent	69,162,000	63,415,000	218,436,000	175,267,000
Net Income			83,000,000	208,000,000
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$93,781,000	$74,067,000	$175,225,000	$189,564,000
Earnings Per Share, Basic	$1.57	$1.45	$4.95	$4.02
Earnings per common share:
Basic			$1.90	$4.77
Earnings Per Share, Diluted	$1.32	$1.25	$4.17	$3.43
Diluted			$1.63	$4.07

SCHEDULE_OF_SHAREBASED_COMPENS

SCHEDULE OF SHARE-BASED COMPENSATION, STOCK OPTIONS AND STOCK APPRECIATION RIGHTS AWARD ACTIVITY (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement By Share-based Payment Award, Options and Stock Appreciation Rights, Outstanding [Roll Forward]
Beginning of Year (in shares)			3,142,021
Grants in Period (in shares)			252,473
Exercises in Period (in shares)			344,446
Forfeitures in Period (in shares)			18,530
End of Period (in shares)	3,031,518		3,031,518
Exercisable (in shares)	2,508,083		2,508,083
Weighted Average Exercise Price, Beginning of Year (in dollars per share)			$45.40
Weighted Average Exercise Price, Grants in Period (in dollars per share)			$72.17
Weighted Average Exercise Price, Exercises in Period (in dollars per share)			$46.88
Weighted Average Exercise Price, Forfeitures in Period (in dollars per share)			$60.74
Weighted Average Exercise Price, End of Period (in dollars per share)	$47.37		$47.37
Weighted Average Exercise Price, Exercisable (in dollars per share)	$43.32		$43.32
Weighted Average Remaining Contractual Term, Outstanding (in years)	5.3		5.3
Weighted Average Remaining Contractual Term, Exercisable (in years)	4.6		4.6
Aggregate Intrinsic Value, Outstanding	$88,397		$88,397
Aggregate Intrinsic Value, Exercisable	$83,305		$83,305
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$32.05	$24.33	$31.33	$27.89

SCHEDULE_OF_SHAREBASED_PAYMENT

SCHEDULE OF SHARE-BASED PAYMENT AWARD, VALUATION ASSUMPTIONS (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate	1.60%	0.60%	0.90%	0.90%
Expected life (in years)	5 years	5 years	5 years	5 years
WESCO expected volatility	48.00%	50.00%	50.00%	50.00%
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	900	850	252,473	257,932
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	0	2,400	69,393	74,724
Performance-based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	0	0	48,058	46,804

SUMMARY_OF_RESTRICTED_STOCK_UN

SUMMARY OF RESTRICTED STOCK UNITS (Details) (Restricted Stock Units (RSUs) [Member], USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested (in shares)	185,690		185,690		187,335
Granted (in shares)	0	2,400	69,393	74,724
Vested (in shares)			-65,705
Forfeited (in shares)			-5,333
Unvested, Weighted Average Fair Value (in dollars per share)	$66.08		$66.08		$52.28
Granted, Weighted Average Fair Value (in dollars per share)			$72.15	$64.27
Vested in Period, Weighted Average Fair Value (in dollars per share)			$33.63
Forfeited in Period, Weighted Average Fair Value (in dollars per share)			$60.11

SUMMARY_OF_PERFORMANCEBASED_AW

SUMMARY OF PERFORMANCE-BASED AWARDS (Details) (Performance-based Awards [Member], USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Performance-based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested (in shares)	92,484		92,484		46,500
Granted (in shares)	0	0	48,058	46,804
Vested (in shares)			0
Forfeited (in shares)			-2,074
Unvested, Weighted Average Fair Value (in dollars per share)	$76.98		$76.98		$75.72
Granted, Weighted Average Fair Value (in dollars per share)			$78.21	$75.72
Vested in Period, Weighted Average Fair Value (in dollars per share)			$0
Forfeited in Period, Weighted Average Fair Value (in dollars per share)			$76.66

SCHEDULE_OF_SHAREBASED_PAYMENT1

SCHEDULE OF SHARE-BASED PAYMENT AWARD, PERFORMANCE-BASED AWARDS, VALUATION ASSUMPTIONS (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
WESCO expected volatility	48.00%	50.00%	50.00%	50.00%
Risk free interest rate	1.60%	0.60%	0.90%	0.90%
Performance-based Awards - Peer Group Total Shareholder Return [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date share price			72.15
WESCO expected volatility			37.80%
Peer group mean volatility			29.10%
Risk free interest rate			0.38%
Correlation			116.80%

STOCKBASED_COMPENSATION_Detail

STOCK-BASED COMPENSATION (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Sep. 30, 2013

Stock Appreciation Rights (SARs) [Member]

Stock Appreciation Rights (SARs) [Member]

Stock Appreciation Rights (SARs) [Member]

Stock Appreciation Rights (SARs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Performance-based Awards [Member]

Performance-based Awards [Member]

Performance-based Awards [Member]

Performance-based Awards - Peer Group Total Shareholder Return [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Granted, Weighted Average Fair Value (in dollars per share)

$32.05

$24.33

$31.33

$27.89

$72.15

$64.27

$78.21

$75.72

Performance-based awards outstanding (in shares)

185,690

187,335

92,484

46,500

46,242

Stock-based compensation expense

$3,700,000

$3,200,000

$12,534,000

$11,722,000

Total unrecognized compensation cost

20,800,000

20,800,000

Compensation cost expected to be recognized over the remainder of 2012

3,600,000

Compensation cost expected to be recognized in 2013

10,900,000

Compensation cost expected to be recognized in 2014

5,500,000

Compensation cost expected to be recognized in 2015

800,000

Total intrinsic value of awards exercised

14,100,000

22,400,000

Cash received from exercise of options

100,000

200,000

Tax benefit associated with exercise of awards

$4,800,000

$5,400,000

SCHEDULE_OF_EARNINGS_PER_SHARE

SCHEDULE OF EARNINGS PER SHARE, BASIC AND DILUTED (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]
Net income (loss) attributable to WESCO International, Inc.	$69,162	$63,415	$218,436	$175,267
Weighted average common shares outstanding used in computing basic earnings per share (in shares)	44,180,000	43,705,000	44,127,000	43,596,000
Common shares issuable upon exercise of dilutive stock options (in shares)	1,067,000	1,032,000	1,088,000	1,199,000
Common shares issuable from contingently convertible debentures (in shares)	7,299,000	6,036,000	7,214,000	6,262,000
Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share (in shares)	52,546,000	50,773,000	52,429,000	51,057,000
Earnings Per Share, Basic and Diluted [Abstract]
Basic (in dollars per share)	$1.57	$1.45	$4.95	$4.02
Diluted (in dollars per share)	$1.32	$1.25	$4.17	$3.43

EARNINGS_PER_SHARE_Details

EARNINGS PER SHARE (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock Appreciation Rights (SARs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	300,000	1,000,000	500,000	1,200,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Weighted Average Exercise Price (in dollars per share)	$71.81	$62.88	$65.29	$64.12
Convertible Debt Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of Dilutive Securities on Earnings Per Share (in dollars per share)	($0.21)	($0.17)	($0.66)	($0.48)
Convertible Debt Securities [Member] | Convertible Senior Debentures Due in 2029 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt Instrument, Convertible, Conversion Price (in dollars per share)	$28.87		$28.87
Earnings Per Share Dilution Limit (in shares)			11,948,894

ACCOUNTS_RECEIVABLE_SECURITIZA1

ACCOUNTS RECEIVABLE SECURITIZATION FACILITY (Details) (Accounts Receivable Securitization Facility [Member], USD $)	0 Months Ended	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 19, 2013	Dec. 31, 2012
Accounts Receivable Securitization Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$500		$475
Line of Credit Facility Maximum Borrowing Capacity Accordion Feature	100
Debt Instrument, Basis Spread on Variable Rate	0.95%		1.10%
Line of Credit Facility, Commitment Fee Percentage	0.45%	0.55%
Long-term Debt	$500		$445
Debt Instrument, Interest Rate, Effective Percentage	1.10%

EMPLOYEE_BENEFIT_PLANS_Details

EMPLOYEE BENEFIT PLANS (Details) (USD $)	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012
Compensation and Retirement Disclosure [Abstract]
Defined Benefit Plan, Contributions by Employer	$22.10	$23.90
Schedule of Employee Benefit Plans [Line Items]
Defined Contribution Plan, Cost Recognized		$25.70	$24.20
UNITED STATES
Schedule of Employee Benefit Plans [Line Items]
Defined Contribution Plan Employer Matching Contribution Percent		50.00%
Defined Contribution Plan Maximum Annual Contribution Per Employee Percent		6.00%
Minimum [Member] | CANADA
Schedule of Employee Benefit Plans [Line Items]
Defined Contribution Plan Maximum Annual Contribution Per Employee Percent		1.00%
Maximum [Member] | CANADA
Schedule of Employee Benefit Plans [Line Items]
Defined Contribution Plan Maximum Annual Contribution Per Employee Percent		7.00%

EMPLOYEE_BENEFIT_PLANS_EMPLOYE

EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS Pension Costs (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Compensation and Retirement Disclosure [Abstract]
Defined Benefit Plan, Contributions by Employer	$22,100,000		$23,900,000
Service cost	996,000	0	3,049,000	0
Interest cost	1,117,000	0	3,422,000	0
Expected return on plan assets	-1,173,000	0	-3,081,000	0
Net periodic benefit cost	$940,000	$0	$3,390,000	$0

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Details) (USD $)	3 Months Ended	6 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2013	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
Damages sought			$50
Damages awarded			36.1
Prejudgment interest awarded			3.9
Post-judgment interest awarded	$0.80	$4.70

INCOME_TAXES_Details

INCOME TAXES (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Effective tax rate	30.90%	29.90%	27.90%	29.80%
Federal statutory rate			35.00%
Discrete adjustments			$0.30	$3.20
Unrecognized tax benefits	23.2		23.2		21.1
Deferred tax asset					28
Unrecognized tax benefits that would impact effective tax rate	23.2		23.2		21.2
Significant change in unrecognized tax benefits that is reasonably possible	17.2		17.2
Reversal of deferred tax asset	15.6		15.6
Liability for interest related to uncertain tax positions	$8.40		$8.40		$8

OTHER_FINANCIAL_INFORMATION_De

OTHER FINANCIAL INFORMATION (Details) (Convertible Senior Debentures Due in 2029 [Member], USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Convertible Senior Debentures Due in 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$344.90

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Condensed Financial Information [Line Items]
Change in Presentation of investments in Affiliates		$480,200,000
Cash and cash equivalents	98,575,000	86,099,000	107,637,000	63,869,000
Trade accounts receivable, net	1,116,007,000	1,036,235,000
Inventories, net	795,917,000	793,974,000
Other current assets	208,171,000	185,529,000
Total current assets	2,218,670,000	2,101,837,000
Intercompany receivables, net	0	0
Property, buildings and equipment, net	201,905,000	210,723,000
Intangible assets, net	457,621,000	496,761,000
Goodwill and other intangibles, net	1,762,331,000	1,777,797,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Other assets	38,944,000	42,511,000
Total assets	4,679,471,000	4,629,629,000
Accounts payable	754,013,000	706,580,000
Short-term debt	32,428,000	30,136,000
Other current liabilities	250,370,000	271,279,000
Total current liabilities	1,036,811,000	1,007,995,000
Intercompany payables, net	0	0
Long-term debt	1,535,464,000	1,695,413,000
Other noncurrent liabilities	368,871,000	372,530,000
Total stockholders' equity	1,738,305,000	1,553,797,000
Stockholders' Equity Attributable to Noncontrolling Interest	-20,000	106,000
Total liabilities and stockholders' equity	4,679,471,000	4,629,629,000
Change in Presentation of Intercompany Receivables, net		679,900,000
Change in Presentation of Cumulative Accrued Interest Payable		198,100,000
Change in Presentation of Non-Current Liabilities		1,600,000
Parent Company [Member]
Condensed Financial Information [Line Items]
Cash and cash equivalents	0	0	0	0
Trade accounts receivable, net	0	0
Inventories, net	0	0
Other current assets	0	0
Total current assets	0	0
Intercompany receivables, net	0	0
Property, buildings and equipment, net	0	0
Intangible assets, net	0	0
Goodwill and other intangibles, net	0	0
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	3,107,052,000	2,918,779,000
Other assets	4,431,000	4,671,000
Total assets	3,111,483,000	2,923,450,000
Accounts payable	0	0
Short-term debt	0	0
Other current liabilities	998,000	16,779,000
Total current liabilities	998,000	16,779,000
Intercompany payables, net	1,170,739,000	1,153,562,000
Long-term debt	173,374,000	171,213,000
Other noncurrent liabilities	28,067,000	28,099,000
Total stockholders' equity	1,738,305,000	1,553,797,000
Stockholders' Equity Attributable to Noncontrolling Interest	0	0
Total liabilities and stockholders' equity	3,111,483,000	2,923,450,000
Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Cash and cash equivalents	45,838,000	52,275,000	75,673,000	44,412,000
Trade accounts receivable, net	0	0
Inventories, net	347,319,000	347,008,000
Other current assets	93,993,000	66,107,000
Total current assets	487,150,000	465,390,000
Intercompany receivables, net	0	0
Property, buildings and equipment, net	59,135,000	58,523,000
Intangible assets, net	5,538,000	6,153,000
Goodwill and other intangibles, net	246,125,000	246,125,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	3,705,286,000	3,590,772,000
Other assets	15,591,000	16,842,000
Total assets	4,518,825,000	4,383,805,000
Accounts payable	413,738,000	401,016,000
Short-term debt	0	0
Other current liabilities	123,014,000	100,956,000
Total current liabilities	536,752,000	501,972,000
Intercompany payables, net	658,281,000	603,336,000
Long-term debt	715,221,000	847,761,000
Other noncurrent liabilities	202,545,000	190,294,000
Total stockholders' equity	2,406,026,000	2,240,442,000
Stockholders' Equity Attributable to Noncontrolling Interest	0	0
Total liabilities and stockholders' equity	4,518,825,000	4,383,805,000
Non-Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Cash and cash equivalents	52,737,000	33,824,000	31,964,000	19,457,000
Trade accounts receivable, net	1,116,007,000	1,036,235,000
Inventories, net	448,598,000	446,966,000
Other current assets	114,178,000	118,404,000
Total current assets	1,731,520,000	1,635,429,000
Intercompany receivables, net	1,829,020,000	1,756,898,000
Property, buildings and equipment, net	142,770,000	152,200,000
Intangible assets, net	452,083,000	490,608,000
Goodwill and other intangibles, net	1,516,206,000	1,531,672,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Other assets	18,922,000	19,656,000
Total assets	5,690,521,000	5,586,463,000
Accounts payable	340,275,000	305,564,000
Short-term debt	32,428,000	30,136,000
Other current liabilities	126,358,000	152,526,000
Total current liabilities	499,061,000	488,226,000
Intercompany payables, net	0	0
Long-term debt	646,869,000	676,439,000
Other noncurrent liabilities	138,259,000	152,795,000
Total stockholders' equity	4,406,312,000	4,269,109,000
Stockholders' Equity Attributable to Noncontrolling Interest	-20,000	106,000
Total liabilities and stockholders' equity	5,690,521,000	5,586,463,000
Consolidation, Eliminations [Member]
Condensed Financial Information [Line Items]
Cash and cash equivalents	0	0	0	0
Trade accounts receivable, net	0	0
Inventories, net	0	0
Other current assets	0	1,018,000
Total current assets	0	1,018,000
Intercompany receivables, net	-1,829,020,000	-1,756,898,000
Property, buildings and equipment, net	0	0
Intangible assets, net	0	0
Goodwill and other intangibles, net	0	0
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	-6,812,338,000	-6,509,551,000
Other assets	0	1,342,000
Total assets	-8,641,358,000	-8,264,089,000
Accounts payable	0	0
Short-term debt	0	0
Other current liabilities	0	1,018,000
Total current liabilities	0	1,018,000
Intercompany payables, net	-1,829,020,000	-1,756,898,000
Long-term debt	0	0
Other noncurrent liabilities	0	1,342,000
Total stockholders' equity	-6,812,338,000	-6,509,551,000
Stockholders' Equity Attributable to Noncontrolling Interest	0	0
Total liabilities and stockholders' equity	($8,641,358,000)	($8,264,089,000)

CONDENSED_CONSOLIDATED_INCOME_

CONDENSED CONSOLIDATED INCOME STATEMENTS (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Condensed Financial Information [Line Items]
Change in Presentation of Net Sales		$2,000,000
Net sales	1,931,260,000	1,656,186,000	5,633,271,000	4,934,938,000
Cost of goods sold	1,535,609,000	1,317,432,000	4,463,991,000	3,940,762,000
Selling, general and administrative expense	255,202,000	225,812,000	748,164,000	685,130,000
Depreciation and amortization	16,803,000	9,910,000	50,673,000	26,431,000
Results of affiliates' operations	0	0	0	0
Interest expense, net	21,304,000	12,654,000	64,999,000	33,093,000
Loss on sale of Argentina business	2,315,000	0	2,315,000	0
Provision for income taxes	30,909,000	26,987,000	84,567,000	74,259,000
Net income (loss)	69,118,000	63,391,000	218,562,000	175,263,000
Less: Net (loss) income attributable to noncontrolling interest	-44,000	-24,000	126,000	-4,000
Net income (loss) attributable to WESCO International, Inc.	69,162,000	63,415,000	218,436,000	175,267,000
Comprehensive Income:
Foreign currency translation adjustment	24,619,000	10,652,000	-43,211,000	14,297,000
Comprehensive income attributable to WESCO International, Inc.	93,781,000	74,067,000	175,225,000	189,564,000
Parent Company [Member]
Condensed Financial Information [Line Items]
Net sales	0	0	0	0
Cost of goods sold	0	0	0	0
Selling, general and administrative expense	19,000	25,000	24,000	49,000
Depreciation and amortization	0	0	0	0
Results of affiliates' operations	73,241,000	68,055,000	231,481,000	187,903,000
Interest expense, net	5,944,000	6,623,000	17,893,000	17,944,000
Loss on sale of Argentina business	0		0
Provision for income taxes	-1,840,000	-1,984,000	-4,998,000	-5,353,000
Net income (loss)	69,118,000	63,391,000	218,562,000	175,263,000
Less: Net (loss) income attributable to noncontrolling interest	0	0	0	0
Net income (loss) attributable to WESCO International, Inc.	69,118,000	63,391,000	218,562,000	175,263,000
Comprehensive Income:
Foreign currency translation adjustment	24,619,000	10,652,000	-43,211,000	14,297,000
Comprehensive income attributable to WESCO International, Inc.	93,737,000	74,043,000	175,351,000	189,560,000
Change in Presentation of Interest Expense		500,000		500,000
Change in Presentation of Income Tax Expense		2,000,000		5,400,000
Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Net sales	878,851,000	868,289,000	2,572,693,000	2,602,688,000
Cost of goods sold	698,965,000	689,462,000	2,047,937,000	2,074,165,000
Selling, general and administrative expense	129,518,000	121,067,000	368,853,000	413,540,000
Depreciation and amortization	4,668,000	3,979,000	13,551,000	11,232,000
Results of affiliates' operations	58,574,000	34,887,000	157,726,000	122,064,000
Interest expense, net	18,823,000	11,886,000	56,667,000	32,200,000
Loss on sale of Argentina business	0		0
Provision for income taxes	19,856,000	16,248,000	34,617,000	27,739,000
Net income (loss)	65,595,000	60,534,000	208,794,000	165,876,000
Less: Net (loss) income attributable to noncontrolling interest	0	0	0	0
Net income (loss) attributable to WESCO International, Inc.	65,595,000	60,534,000	208,794,000	165,876,000
Comprehensive Income:
Foreign currency translation adjustment	24,619,000	10,652,000	-43,211,000	14,297,000
Comprehensive income attributable to WESCO International, Inc.	90,214,000	71,186,000	165,583,000	180,173,000
Change in Presentation of Interest Expense		8,200,000		24,500,000
Change in Presentation of Income Tax Expense		8,400,000		40,000,000
Non-Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Net sales	1,082,585,000	818,213,000	3,154,350,000	2,432,239,000
Cost of goods sold	866,820,000	658,286,000	2,509,826,000	1,966,586,000
Selling, general and administrative expense	125,665,000	104,720,000	379,287,000	271,541,000
Depreciation and amortization	12,135,000	5,931,000	37,122,000	15,199,000
Results of affiliates' operations	0	0	0	0
Interest expense, net	-3,463,000	-5,855,000	-9,561,000	-17,051,000
Loss on sale of Argentina business	-2,315,000		-2,315,000
Provision for income taxes	12,893,000	12,723,000	54,948,000	51,873,000
Net income (loss)	66,220,000	42,408,000	180,413,000	144,091,000
Less: Net (loss) income attributable to noncontrolling interest	-44,000	-24,000	126,000	-4,000
Net income (loss) attributable to WESCO International, Inc.	66,264,000	42,432,000	180,287,000	144,095,000
Comprehensive Income:
Foreign currency translation adjustment	24,619,000	10,652,000	-43,211,000	14,297,000
Comprehensive income attributable to WESCO International, Inc.	90,883,000	53,084,000	137,076,000	158,392,000
Change in Presentation of Interest Expense		8,700,000		25,000,000
Change in Presentation of Income Tax Expense		10,400,000		45,400,000
Consolidation, Eliminations [Member]
Condensed Financial Information [Line Items]
Net sales	-30,176,000	-30,316,000	-93,772,000	-99,989,000
Cost of goods sold	-30,176,000	-30,316,000	-93,772,000	-99,989,000
Selling, general and administrative expense	0	0	0	0
Depreciation and amortization	0	0	0	0
Results of affiliates' operations	-131,815,000	-102,942,000	-389,207,000	-309,967,000
Interest expense, net	0	0	0	0
Loss on sale of Argentina business	0		0
Provision for income taxes	0	0	0	0
Net income (loss)	-131,815,000	-102,942,000	-389,207,000	-309,967,000
Less: Net (loss) income attributable to noncontrolling interest	0	0	0	0
Net income (loss) attributable to WESCO International, Inc.	-131,815,000	-102,942,000	-389,207,000	-309,967,000
Comprehensive Income:
Foreign currency translation adjustment	-49,238,000	-21,304,000	86,422,000	-28,594,000
Comprehensive income attributable to WESCO International, Inc.	($181,053,000)	($124,246,000)	($302,785,000)	($338,561,000)

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Condensed Financial Information [Line Items]
Change in Presentation of Cash Paid for Acquisitions		$58,600,000
Net cash (used) provided by operating activities	179,669,000	189,683,000
Investing Activities:
Capital expenditures	-20,472,000	-19,469,000
Acquisition payments	0	-201,123,000
Other	-1,205,000	0
Proceeds from sale of assets	10,481,000	51,000
Other	1,205,000	0
Net cash used in investing activities	-11,196,000	-220,541,000
Financing Activities:
Borrowings	802,442,000	761,838,000
Repayments	-949,370,000	-693,331,000
Condensed Proceeds from (Payments for) Other Financing Activities	-7,592,000	5,884,000
Other financing activities, net	-7,188,000	-4,308,000
Net cash used in financing activities	-154,520,000	74,391,000
Effect of exchange rate changes on cash and cash equivalents	-1,477,000	235,000
Net change in cash and cash equivalents	12,476,000	43,768,000
Cash and cash equivalents at the beginning of period	86,099,000	63,869,000
Cash and cash equivalents at the end of period	98,575,000	107,637,000
Change in Presentation of Advance to Parent		5,500,000
Parent Company [Member]
Condensed Financial Information [Line Items]
Net cash (used) provided by operating activities	-14,515,000	-3,020,000
Investing Activities:
Capital expenditures	0	0
Acquisition payments	0	0
Proceeds from sale of assets	0	0
Other		0
Net cash used in investing activities	0	0
Financing Activities:
Borrowings	17,176,000	5,489,000
Repayments		0
Condensed Proceeds from (Payments for) Other Financing Activities	-2,661,000	-2,469,000
Net cash used in financing activities	14,515,000	3,020,000
Effect of exchange rate changes on cash and cash equivalents	0	0
Net change in cash and cash equivalents	0	0
Cash and cash equivalents at the beginning of period	0	0
Cash and cash equivalents at the end of period	0	0
Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Net cash (used) provided by operating activities	163,190,000	272,123,000
Investing Activities:
Capital expenditures	-16,421,000	-15,654,000
Acquisition payments	0	-142,483,000
Proceeds from sale of assets	0	51,000
Other	17,176,000	64,129,000
Net cash used in investing activities	-33,597,000	-222,215,000
Financing Activities:
Borrowings	508,213,000	177,300,000
Repayments	640,713,000	204,300,000
Condensed Proceeds from (Payments for) Other Financing Activities	-3,530,000	8,353,000
Net cash used in financing activities	-136,030,000	-18,647,000
Effect of exchange rate changes on cash and cash equivalents	0	0
Net change in cash and cash equivalents	-6,437,000	31,261,000
Cash and cash equivalents at the beginning of period	52,275,000	44,412,000
Cash and cash equivalents at the end of period	45,838,000	75,673,000
Change in Presentation of Proceeds from Issuance of Intercompany Debt		177,300,000
Change in Presentation of Repayments of Intercompany Debt		204,300,000
Non-Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Net cash (used) provided by operating activities	30,994,000	-79,420,000
Investing Activities:
Capital expenditures	-4,051,000	-3,815,000
Acquisition payments	0	-58,640,000
Proceeds from sale of assets	10,481,000	0
Other	1,205,000	0
Net cash used in investing activities	5,225,000	-62,455,000
Financing Activities:
Borrowings	294,229,000	643,178,000
Repayments	308,657,000	489,031,000
Condensed Proceeds from (Payments for) Other Financing Activities	-1,401,000	0
Net cash used in financing activities	-15,829,000	154,147,000
Effect of exchange rate changes on cash and cash equivalents	-1,477,000	235,000
Net change in cash and cash equivalents	18,913,000	12,507,000
Cash and cash equivalents at the beginning of period	33,824,000	19,457,000
Cash and cash equivalents at the end of period	52,737,000	31,964,000
Change in Presentation of Proceeds from Issuance of Intercompany Debt		643,200,000
Change in Presentation of Repayments of Intercompany Debt		489,000,000
Consolidation, Eliminations [Member]
Condensed Financial Information [Line Items]
Net cash (used) provided by operating activities	0	0
Investing Activities:
Capital expenditures	0	0
Acquisition payments	0	0
Proceeds from sale of assets	0	0
Other	-17,176,000	-64,129,000
Net cash used in investing activities	17,176,000	64,129,000
Financing Activities:
Borrowings	-17,176,000	-64,129,000
Repayments		0
Condensed Proceeds from (Payments for) Other Financing Activities	0	0
Net cash used in financing activities	-17,176,000	-64,129,000
Effect of exchange rate changes on cash and cash equivalents	0	0
Net change in cash and cash equivalents	0	0
Cash and cash equivalents at the beginning of period	0	0
Cash and cash equivalents at the end of period	$0	$0