WESCO International (WCC) 10-Q 3 Nov 14 2014 Q3 Quarterly report Financial data

DOCUMENT_AND_ENTITY_INFORMATIO

DOCUMENT AND ENTITY INFORMATION Document	9 Months Ended
	Sep. 30, 2014	Oct. 30, 2014
Entity [Abstract]	'	'
Entity Registrant Name	'WESCO INTERNATIONAL INC.	'
Entity Central Index Key	'0000929008	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	44,481,394

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2012
Adjustment to other assets / deferred tax liabilities	'	$24,700,000	'
Adjustment to prepaids and OCA / OCL	'	7,100,000	'
Adjustment to deferred tax assets and liabilities	'	'	16,200,000
Deferred Tax Assets, Gross	'	'	17,500,000
Current Assets:	'	'	'
Cash and cash equivalents	110,368,000	123,725,000	86,099,000
Trade accounts receivable, net of allowance for doubtful accounts of $23,069 and $19,309 in 2014 and 2013, respectively	1,218,759,000	1,045,054,000	'
Other accounts receivable	131,724,000	130,043,000	'
Inventories, net	846,166,000	787,324,000	'
Current deferred income taxes	35,031,000	44,691,000	'
Prepaid expenses and other current assets	107,989,000	74,778,000	'
Total current assets	2,450,037,000	2,205,615,000	'
Property, buildings and equipment, net of accumulated depreciation of $229,041 and $213,758 in 2014 and 2013, respectively	191,393,000	198,654,000	'
Intangible assets, net	452,140,000	439,167,000	'
Goodwill	1,759,833,000	1,734,391,000	'
Other assets	52,065,000	71,066,000	'
Total assets	4,905,468,000	4,648,893,000	'
Current Liabilities:	'	'	'
Accounts payable	842,779,000	735,097,000	'
Accrued payroll and benefit costs	63,892,000	56,548,000	'
Short-term debt	43,006,000	37,551,000	'
Current portion of long-term debt	2,393,000	2,510,000	'
Other current liabilities	174,611,000	219,957,000	140,600,000
Total current liabilities	1,126,681,000	1,051,663,000	'
Long-term debt, net of discount of $171,547 and $174,686 in 2014 and 2013, respectively	1,471,774,000	1,447,634,000	'
Other noncurrent liabilities	48,541,000	43,471,000	'
Deferred income taxes	349,827,000	341,334,000	'
Total liabilities	2,996,823,000	2,884,102,000	'
Commitments and Contingencies	'	'	'
Stockholders' Equity:	'	'	'
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding	0	0	'
Additional capital	1,098,458,000	1,082,772,000	'
Retained earnings	1,569,531,000	1,368,386,000	'
Treasury stock, at cost; 18,247,467 and 18,179,275 shares in 2014 and 2013, respectively	-616,075,000	-610,430,000	'
Accumulated other comprehensive income	-143,814,000	-76,543,000	'
Total WESCO International stockholders' equity	1,908,645,000	1,764,791,000	'
Noncontrolling interest	-82,000	-18,000	'
Total stockholders' equity	1,908,727,000	1,764,809,000	'
Total liabilities and stockholders' equity	4,905,468,000	4,648,893,000	'
Deferred Tax Liabilities, Net	'	'	316,700,000
Adjustment to income taxes receivable and OCL	'	'	6,000,000
Income Taxes Receivable	'	'	14,800,000
Common Stock [Member]	'	'	'
Stockholders' Equity:	'	'	'
Common stock	584,000	581,000	'
Common Class B [Member]	'	'	'
Stockholders' Equity:	'	'	'
Common stock	$43,000	$43,000	'

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parentheticals) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Allowance for doubtful accounts	$23,069	$19,309
Accumulated depreciation	229,041	213,758
Debt discount	$171,547	$174,686
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)	58,388,696	58,107,304
Common stock, shares outstanding (in shares)	44,480,660	44,267,460
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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]	'	'	'	'
Net sales	$2,078,150	$1,931,260	$5,894,141	$5,633,271
Cost of goods sold	1,655,787	1,535,609	4,685,257	4,463,991
Selling, general and administrative expense	271,697	255,202	815,869	748,164
Depreciation and amortization	17,418	16,803	50,976	50,673
Income from operations	133,248	123,646	342,039	370,443
Interest expense, net	20,798	21,304	61,823	64,999
Loss on sale of Argentina business	0	-2,315	0	-2,315
Income before income taxes	112,450	100,027	280,216	303,129
Provision for income taxes	31,632	30,909	78,757	84,567
Net income	80,818	69,118	201,459	218,562
Net (loss) income attributable to noncontrolling interest	2	-44	-64	126
Net income attributable to WESCO International, Inc.	80,816	69,162	201,523	218,436
Comprehensive Income:	'	'	'	'
Foreign currency translation adjustment	-63,794	24,619	-67,271	-43,211
Comprehensive income attributable to WESCO International, Inc.	$17,022	$93,781	$134,252	$175,225
Earnings per share attributable to WESCO International, Inc.	'	'	'	'
Basic (in dollars per share)	$1.82	$1.57	$4.54	$4.95
Diluted (in dollars per share)	$1.52	$1.32	$3.78	$4.17

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Operating Activities:	'	'
Net income	$201,459	$218,562
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization	50,976	50,673
Deferred income taxes	17,847	36,486
Other operating activities, net	9,455	15,019
Changes in assets and liabilities	'	'
Trade receivables, net	-174,967	-91,301
Other accounts receivable	-2,779	-32,580
Inventories, net	-54,053	-11,743
Prepaid expenses and other current assets	-34,906	-5,881
Accounts payable	106,886	50,146
Other current and noncurrent liabilities	19,902	-49,712
Net cash provided by operating activities	139,820	179,669
Investing Activities:	'	'
Capital expenditures	-16,036	-20,472
Acquisition payments, net of cash acquired	-138,805	0
Other investing activities	5,444	9,276
Net cash used in investing activities	-149,397	-11,196
Financing Activities:	'	'
Proceeds from issuance of short-term debt	49,727	42,972
Repayments of short-term debt	-42,168	-33,808
Proceeds from issuance of long-term debt	912,146	759,470
Repayments of Long-term Debt	-885,408	-915,562
Other financing activities, net	-9,312	-7,592
Net cash used in financing activities	-4,410	-154,520
Effect of exchange rate on cash and cash equivalents	630	-1,477
Net change in cash and cash equivalents	-13,357	12,476
Cash and cash equivalents at the beginning of period	123,725	86,099
Cash and cash equivalents at the end of period	110,368	98,575
Payments for Previous Acquisition	($29,395)	$0

ORGANIZATION

ORGANIZATION	9 Months Ended
	Sep. 30, 2014
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 75,000 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, 2014
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 2013 Annual Report on Form 10-K filed with the SEC. The December 31, 2013 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, 2014, the unaudited condensed consolidated statements of income and comprehensive income for the three and nine months ended September 30, 2014 and 2013, respectively, and the unaudited condensed consolidated statements of cash flows for the nine months ended September 30, 2014 and 2013, 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.
	Revision
	Certain amounts in the Company's consolidated balance sheet as of December 31, 2013, as presented herein, have been revised to appropriately present current and non-current deferred tax balances as well as current taxes refundable/payable in accordance with ASC 740, "Income Taxes".  Specifically, other assets and deferred income tax liabilities each increased by $24.7 million at December 31, 2013.  Additionally, prepaid expenses and other current assets increased by $7.1 million with a corresponding increase to other current liabilities of $7.1 million at December 31, 2013.  The Company also revised its consolidated balance sheet as of December 31, 2012, which is not presented herein, for the same items.  Deferred income tax assets and liabilities each increased by $16.2 million to $17.5 million and $316.7 million, respectively, at December 31, 2012. Income taxes receivable and other current liabilities each increased by $6.0 million to $14.8 million and $140.6 million, respectively, at December 31, 2012.
	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, 2014, the carrying value of WESCO’s 6.0% Convertible Senior Debentures due 2029 (the "2029 Debentures") was $176.7 million and the fair value was approximately $1.0 billion. At December 31, 2013, the carrying value of WESCO’s 2029 Debentures was $174.1 million and the fair value was approximately $1.1 billion. 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.
	Recently Issued Accounting Pronouncements
	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 assets 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 adopted this guidance in 2014. Adoption of this guidance did not have a material impact on WESCO's financial position, results of operations or cash flows.
	In May 2014, the FASB and International Accounting Standards Board ("IASB") issued a converged final standard on the recognition of revenue from contracts with customers. This updated guidance provides a framework for addressing revenue recognition issues and replaces almost all existing revenue recognition guidance in current U.S. generally accepted accounting principles. The core principle of the new standard is for companies to recognize revenue to depict the transfer of goods or services to customers in amounts that reflect the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard will also result in enhanced disclosures about revenue, provide guidance for transactions that were not previously addressed comprehensively, and improve guidance for multiple-element arrangements. This guidance is effective for interim and annual periods beginning after December 15, 2016. Management has not yet evaluated the future impact of this guidance on WESCO's financial position, results of operations or cash flows.

ACQUISITIONS

ACQUISITIONS	9 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
ACQUISITIONS	'
	ACQUISITIONS
	The following table sets forth the consideration paid for acquisitions:
	Amounts in thousands	Nine Months Ended September 30, 2014
	Fair value of assets acquired	$	153,430
	Fair value of liabilities assumed	14,625
	Cash paid for acquisitions	$	138,805
	The fair values of assets acquired and liabilities assumed were based upon preliminary calculations and valuations. Our estimates and assumptions for our preliminary purchase price allocation are subject to change as we obtain additional information for our estimates during the respective measurement periods (up to one year from the respective acquisition dates).
	2014 Acquisitions of LaPrairie, Inc., Hazmasters, Inc., and Hi-Line Utility Supply
	On February 3, 2014, WESCO Distribution, Inc., through its wholly-owned Canadian subsidiary, completed the acquisition of LaPrairie, Inc. ("LaPrairie"), a wholesale distributor of electrical products that services the transmission, distribution, and substation needs of utilities and utility contractors with approximately $30 million in annual sales from a single location in Newmarket, Ontario. WESCO funded the purchase price paid at closing with cash. The purchase price was allocated to the respective assets and liabilities based upon their estimated fair values as of the acquisition date. The preliminary fair value of intangibles was determined by management and the allocation resulted in intangible assets of $11.0 million and goodwill of $8.9 million. Management believes the majority of goodwill will be deductible for tax purposes.
	On March 17, 2014, WESCO Distribution, Inc., through its wholly-owned Canadian subsidiary, completed the acquisition of Hazmasters, Inc. ("Hazmasters"), a leading independent Canadian distributor of safety products servicing customers in the industrial, construction, commercial, institution, and government markets with approximately $80 million in annual sales from 14 branches across Canada. WESCO funded the purchase price paid at closing with cash and borrowings under the Revolving Credit Facility. The purchase price was allocated to the respective assets and liabilities based upon their estimated fair values as of the acquisition date. The preliminary fair value of intangibles was estimated by management and the allocation resulted in intangible assets of $28.1 million and goodwill of $29.1 million which is not deductible for tax purposes.
	On June 11, 2014, WESCO Distribution, Inc., completed the acquisition of Hi-Line Utility Supply ("Hi-Line"), a provider of utility MRO and safety products, as well as rubber goods testing and certification services, with approximately $30 million in annual sales from locations in Chicago, Illinois and Millbury, Massachusetts.  WESCO funded the purchase price paid at closing with cash and borrowings under our variable rate credit facilities.  The purchase price was allocated to the respective assets and liabilities based upon their estimated fair values as of the acquisition date.  The preliminary fair value of intangibles was estimated by management and the allocation resulted in intangible assets of $16.5 million and goodwill of $21.6 million.  Management believes the majority of goodwill will be deductible for tax purposes.
	For all acquisitions made in the first nine months of 2014, the intangible assets include customer relationships of $40.0 million amortized over 2 to 12 years, supplier relationships of $3.2 million amortized over 10 years, trademarks of $12.1 million, and other intangibles of $0.3 million as of September 30, 2014. Certain trademarks have been assigned an indefinite life while others are amortized over 5 years. No residual value is estimated for the intangible assets being amortized.

STOCKBASED_COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Sep. 30, 2014
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, 2014 and 2013, WESCO granted the following stock-settled stock appreciation rights, restricted stock units and performance-based awards at the following weighted average fair values and assumptions:
		Three Months Ended								Nine Months Ended
		September 30,				September 30,				September 30,				September 30,
		2014				2013				2014				2013
	Stock-settled appreciation rights granted	—				900				274,508				252,473
	Weighted average fair value	$	—			$	32.05			$	30.64			$	31.33
	Restricted stock units granted	611				—				63,117				69,393
	Weighted average fair value	$	81.88			$	—			$	85.32			$	72.15
	Performance-based awards granted	—				—				44,046				48,058
	Weighted average fair value	$	—			$	—			$	86.65			$	78.21
	Risk free interest rate	—		%		1.6		%		1.5		%		0.9		%
	Expected life (in years)	0				5				5				5
	Expected volatility	—		%		48		%		39		%		50		%
	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, 2014:
		Awards			Weighted				Weighted			Aggregate
					Average				Average			Intrinsic
					Exercise				Remaining			Value
					Price				Contractual Term (In Years)			(In thousands)
	Outstanding at December 31, 2013	2,715,651			$	45.93
	Granted	274,508			85.35
	Exercised	(452,795	)		40.8
	Forfeited	(20,375	)		70.86
	Outstanding at September 30, 2014	2,516,989			50.95				5.5			$	70,664
	Exercisable at September 30, 2014	2,013,895			$	44.18			4.7			$	68,633
	The following table sets forth a summary of restricted stock units and related information for the nine months ended September 30, 2014:
		Awards			Weighted
					Average
					Fair
					Value
	Unvested at December 31, 2013	184,746			$	66.08
	Granted	63,117			85.32
	Vested	(51,287	)		60.85
	Forfeited	(9,620	)		68.9
	Unvested at September 30, 2014	186,956			$	73.86
	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, 2014:
		Awards			Weighted
					Average
					Fair
					Value
	Unvested at December 31, 2013	92,484			$	76.98
	Granted	44,046			86.65
	Vested	—			—
	Forfeited	(6,526	)		77.87
	Unvested at September 30, 2014	130,004			$	80.21
	The performance-based awards in the table above include 65,002 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, 2014 was estimated using the following weighted-average assumptions:
	Weighted Average Assumptions
	Grant date share price	$	86.65
	WESCO expected volatility	35.4		%
	Peer group median volatility	28.7		%
	Risk-free interest rate	0.62		%
	Correlation	103.1		%
	Vesting of the remaining 65,002 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 $2.5 million and $3.7 million of non-cash stock-based compensation expense, which is included in selling, general and administrative expenses, for the three months ended September 30, 2014 and 2013, respectively. WESCO recognized $11.0 million and $12.5 million of non-cash stock-based compensation expense, which is included in selling, general and administrative expenses, for the nine months ended September 30, 2014 and 2013, respectively. As of September 30, 2014, there was $20.9 million of total unrecognized compensation cost related to non-vested stock-based compensation arrangements for all awards previously made, of which approximately $3.8 million is expected to be recognized over the remainder of 2014, $10.6 million in 2015, $5.8 million in 2016 and $0.7 million in 2017.
	During the nine months ended September 30, 2014 and 2013, the total intrinsic value of awards exercised was $24.2 million and $14.1 million, respectively. The total amount of cash received from the exercise of options was $0.8 million for the nine months ended September 30, 2014 and less than $0.1 million for the nine months ended September 30, 2013. The tax benefit associated with the exercise of awards for the nine months ended September 30, 2014 and 2013 totaled $9.1 million and $4.8 million, respectively, and was recorded as an increase to additional paid-in capital.

EARNINGS_PER_SHARE

EARNINGS PER SHARE	9 Months Ended
	Sep. 30, 2014
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,
	Amounts in thousands, except per share data	2014		2013
	Net income attributable to WESCO International, Inc.	$	80,816	$	69,162
	Weighted average common shares outstanding used in computing basic earnings per share	44,475		44,180
	Common shares issuable upon exercise of dilutive equity awards	990		1,067
	Common shares issuable from contingently convertible debentures (see below for basis of calculation)	7,778		7,299
	Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	53,243		52,546
	Earnings per share attributable to WESCO International, Inc.
	Basic	$	1.82	$	1.57
	Diluted	$	1.52	$	1.32
		Nine Months Ended
		September 30,
	Amounts in thousands, except per share data	2014		2013
	Net income attributable to WESCO International, Inc.	$	201,523	$	218,436
	Weighted average common shares outstanding used in computing basic earnings per share	44,425		44,127
	Common shares issuable upon exercise of dilutive equity awards	1,036		1,088
	Common shares issuable from contingently convertible debentures (see below for basis of calculation)	7,901		7,214
	Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	53,362		52,429
	Earnings per share attributable to WESCO International, Inc.
	Basic	$	4.54	$	4.95
	Diluted	$	3.78	$	4.17
	For the three and nine months ended September 30, 2014, the computation of diluted earnings per share attributable to WESCO International, Inc. excluded approximately 0.3 million and 0.5 million stock-settled stock appreciation rights at weighted average exercise prices of $84.47 per share and $79.29 per share, respectively. 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. 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 11,948,374 shares for the 2029 Debentures. For the three and nine months ended September 30, 2014, the effect of the 2029 Debentures on diluted earnings per share attributable to WESCO International, Inc. was a decrease of $0.26 and $0.65, respectively. 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.

EMPLOYEE_BENEFIT_PLANS

EMPLOYEE BENEFIT PLANS	9 Months Ended
	Sep. 30, 2014
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, 2014 and 2013, WESCO incurred charges of $23.3 million and $25.7 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, 2014 and 2013:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
	Amounts in thousands	2014			2013			2014			2013
	Service cost	$	912		$	996		$	2,712		$	3,049
	Interest cost	1,172			1,117			3,486			3,422
	Expected return on plan assets	(1,380		)	(1,173		)	(4,103		)	(3,081		)
	Net periodic benefit cost	$	704		$	940		$	2,095		$	3,390
	During the three and nine month periods ended September 30, 2014, the Company made cash contributions of $0.5 million and $1.7 million, respectively, to its defined benefit plans. During the three and nine month periods 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, 2014
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.  As a result, the Company recorded a $36.1 million charge to selling, general and administrative expenses in 2012. 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. Final judgment was entered by the court on July 16, 2013, and the Company is appealing the judgment. As of September 30, 2014, the Company recorded a liability and a corresponding receivable in the amount of $8.7 million for all prejudgment and post-judgment interest accrued in connection with this matter. The judgment may increase or decrease based on the outcome of the appellate proceedings that cannot be predicted with certainty.
	WESCO is subject to the laws and regulations of states and other jurisdictions concerning the identification, reporting and escheatment (the transfer of property to the state) of unclaimed or abandoned funds, and is subject to audit and examination for compliance with these requirements.  The Company is currently being examined by a third party auditor for compliance with unclaimed property laws and has accrued an amount based on the facts currently known to the Company.
	In October 2014, WESCO was notified that the New York County District Attorney’s Office is conducting a criminal investigation involving minority and disadvantaged business contracting practices in the construction industry in New York City and that various contractors, minority and disadvantaged business firms, and their material suppliers, including the Company, are a part of this investigation. The Company has commenced an internal review of this matter and intends to cooperate with the government investigation. The Company cannot predict the outcome or impact of the matter at this time, but could be subject to fines, penalties or other adverse consequences. Based on the facts currently known to the Company, it cannot reasonably estimate a range of exposure to potential liability at this time, but does not believe that this matter is likely to have a material effect on the Company, its financial condition or liquidity.

INCOME_TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
INCOME TAXES	'
	INCOME TAXES
	The effective tax rate for the three and nine months ended September 30, 2014 was 28.1%. The effective tax rate for the three and nine months ended September 30, 2013 was 30.9% and 27.9%, respectively. WESCO’s effective tax rate is lower than the federal statutory rate of 35% primarily due to benefits resulting from the tax effect of intercompany financing and lower rates on foreign earnings, which are partially offset by nondeductible expenses and state taxes. The liabilities related to uncertain tax positions increased in the quarter ended September 30, 2014 by $4.8 million, net. This increase is primarily related to temporary items, which did not have a material impact on the effective tax rate for the three and nine months ended September 30, 2014.

OTHER_FINANCIAL_INFORMATION

OTHER FINANCIAL INFORMATION	9 Months Ended
	Sep. 30, 2014
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.
	WESCO Distribution has outstanding $500 million in aggregate principal amount of 5.375% Senior Notes due 2021 (the "2021 Notes"). The 2021 Notes are unsecured senior obligations of WESCO Distribution and are guaranteed on a senior unsecured basis by WESCO International.
	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)
	Amounts in thousands	September 30, 2014
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Cash and cash equivalents	$	—		$	37,639		$	72,729		$	—		$	110,368
	Trade accounts receivable, net	—			—			1,218,759			—			1,218,759
	Inventories, net	—			380,584			465,582			—			846,166
	Other current assets	18			172,936			145,653			(43,863		)	274,744
	Total current assets	18			591,159			1,902,723			(43,863		)	2,450,037
	Intercompany receivables, net	—			—			1,833,480			(1,833,480		)	—
	Property, buildings and equipment, net	—			57,966			133,427			—			191,393
	Intangible assets, net	—			4,901			447,239			—			452,140
	Goodwill	—			246,771			1,513,062			—			1,759,833
	Investments in affiliates	3,284,749			3,820,458			—			(7,105,207		)	—
	Other noncurrent assets	4,152			13,586			34,327			—			52,065
	Total assets	$	3,288,919		$	4,734,841		$	5,864,258		$	(8,982,550	)	$	4,905,468
	Accounts payable	$	—		$	482,892		$	359,887		$	—		$	842,779
	Short-term debt	—			—			43,006			—			43,006
	Other current liabilities	11,533			114,565			158,661			(43,863		)	240,896
	Total current liabilities	11,533			597,457			561,554			(43,863		)	1,126,681
	Intercompany payables, net	1,174,355			659,125			—			(1,833,480		)	—
	Long-term debt	176,691			680,618			614,465			—			1,471,774
	Other noncurrent liabilities	17,613			234,121			146,634			—			398,368
	Total WESCO International stockholders' equity	1,908,727			2,563,520			4,541,687			(7,105,207		)	1,908,727
	Noncontrolling interest	—			—			(82		)	—			(82		)
	Total liabilities and stockholders’ equity	$	3,288,919		$	4,734,841		$	5,864,258		$	(8,982,550	)	$	4,905,468
	WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
	CONDENSED CONSOLIDATING BALANCE SHEETS
	(unaudited)
	Amounts in thousands	December 31, 2013
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Cash and cash equivalents	$	—		$	31,695		$	92,030		$	—		$	123,725
	Trade accounts receivable, net	—			—			1,045,054			—			1,045,054
	Inventories, net	—			351,242			436,082			—			787,324
	Other current assets	22			166,540			127,439			(44,489		)	249,512
	Total current assets	22			549,477			1,700,605			(44,489		)	2,205,615
	Intercompany receivables, net	—			—			1,906,785			(1,906,785		)	—
	Property, buildings and equipment, net	—			59,569			139,085			—			198,654
	Intangible assets, net	—			5,404			433,763			—			439,167
	Goodwill	—			246,125			1,488,266			—			1,734,391
	Investments in affiliates	3,137,418			3,722,902			—			(6,860,320		)	—
	Other noncurrent assets	4,361			15,627			51,078			—			71,066
	Total assets	$	3,141,801		$	4,599,104		$	5,719,582		$	(8,811,594	)	$	4,648,893
	Accounts payable	$	—		$	410,017		$	325,080		$	—		$	735,097
	Short-term debt	—			—			37,551			—			37,551
	Other current liabilities	11,920			114,894			196,690			(44,489		)	279,015
	Total current liabilities	11,920			524,911			559,321			(44,489		)	1,051,663
	Intercompany payables, net	1,168,507			738,278			—			(1,906,785		)	—
	Long-term debt	174,149			675,424			598,061			—			1,447,634
	Other noncurrent liabilities	22,416			220,650			141,739			—			384,805
	Total WESCO International stockholders' equity	1,764,809			2,439,841			4,420,479			(6,860,320		)	1,764,809
	Noncontrolling interest	—			—			(18		)	—			(18		)
Total liabilities and stockholders’ equity	$	3,141,801		$	4,599,104		$	5,719,582		$	(8,811,594	)	$	4,648,893
WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENTS OF INCOME AND COMPREHENSIVE INCOME
(unaudited)
Amounts in thousands	Three Months Ended September 30, 2014
	WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
	International,			Distribution,			Subsidiaries			and
	Inc.			Inc.						Eliminating
										Entries
Net sales	$	—		$	932,948		$	1,174,935		$	(29,733	)	$	2,078,150
Cost of goods sold	—			747,219			938,301			(29,733		)	1,655,787
Selling, general and administrative expenses	—			141,924			129,773			—			271,697
Depreciation and amortization	—			4,670			12,748			—			17,418
Results of affiliates’ operations	85,219			62,611			—			(147,830		)	—
Interest expense, net	6,123			18,765			(4,090		)	—			20,798
Provision for income taxes	(1,722		)	5,733			27,621			—			31,632
Net income	80,818			77,248			70,582			(147,830		)	80,818
Less: Net loss attributable to noncontrolling interest	—			—			2			—			2
Net income attributable to WESCO International, Inc.	$	80,818		$	77,248		$	70,580		$	(147,830	)	$	80,816
Comprehensive income:
Foreign currency translation adjustment	(63,794		)	(63,794		)	(63,794		)	127,588			(63,794		)
Comprehensive income attributable to WESCO International, Inc.	$	17,024		$	13,454		$	6,786		$	(20,242	)	$	17,022
Amounts in thousands	Three Months Ended September 30, 2013
	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	69,118			65,595			66,220			(131,815		)	69,118
Less: Net income attributable to noncontrolling interest	—			—			(44		)	—			(44		)
Net income 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
WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENTS OF INCOME AND COMPREHENSIVE INCOME
(unaudited)
Amounts in thousands	Nine Months Ended September 30, 2014
	WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
	International,			Distribution,			Subsidiaries			and
	Inc.			Inc.						Eliminating
										Entries
Net sales	$	—		$	2,656,619		$	3,323,237		$	(85,715	)	$	5,894,141
Cost of goods sold	—			2,126,743			2,644,229			(85,715		)	4,685,257
Selling, general and administrative expenses	2			423,371			392,496			—			815,869
Depreciation and amortization	—			14,284			36,692			—			50,976
Results of affiliates’ operations	214,601			164,826			—			(379,427		)	—
Interest expense, net	18,277			55,854			(12,308		)	—			61,823
Provision for income taxes	(5,137		)	10,244			73,650			—			78,757
Net income	201,459			190,949			188,478			(379,427		)	201,459
Less: Net income attributable to noncontrolling interest	—			—			(64		)	—			(64		)
Net income attributable to WESCO International, Inc.	$	201,459		$	190,949		$	188,542		$	(379,427	)	$	201,523
Comprehensive income:
Foreign currency translation adjustment	(67,271		)	(67,271		)	(67,271		)	134,542			(67,271		)
Comprehensive income attributable to WESCO International, Inc.	$	134,188		$	123,678		$	121,271		$	(244,885	)	$	134,252
Amounts in thousands	Nine Months Ended September 30, 2013
	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	231,482			157,726			—			(389,208		)	—
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	(4,997		)	34,617			54,947			—			84,567
Net income	218,562			208,794			180,414			(389,208		)	218,562
Less: Net income attributable to noncontrolling interest	—			—			126			—			126
Net income attributable to WESCO International, Inc.	$	218,562		$	208,794		$	180,288		$	(389,208	)	$	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		$	137,077		$	(302,786	)	$	175,225
WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS
(unaudited)
Amounts in thousands	Nine Months Ended September 30, 2014
	WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
	International,			Distribution,			Subsidiaries			and Eliminating
	Inc.			Inc.						Entries
Net cash (used) provided by operating activities	$	(5,202	)	$	68,291		$	76,731		$	—		$	139,820
Investing activities:
Capital expenditures	—			(10,811		)	(5,225		)	—			(16,036		)
Acquisition payments	—			(42,132		)	(96,673		)	—			(138,805		)
Other	—			(5,842		)	5,444			5,842			5,444
Net cash used in investing activities	—			(58,785		)	(96,454		)	5,842			(149,397		)
Financing activities:
Borrowings	6,517			645,411			316,462			(6,517		)	961,873
Repayments	(675		)	(640,411		)	(316,560		)	675			(956,971		)
Other	(640		)	(8,562		)	(110		)	—			(9,312		)
Net cash provided (used) by financing activities	5,202			(3,562		)	(208		)	(5,842		)	(4,410		)
Effect of exchange rate changes on cash and cash equivalents	—			—			630			—			630
Net change in cash and cash equivalents	—			5,944			(19,301		)	—			(13,357		)
Cash and cash equivalents at the beginning of year	—			31,695			92,030			—			123,725
Cash and cash equivalents at the end of period	$	—		$	37,639		$	72,729		$	—		$	110,368
WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS
(unaudited)
Amounts in thousands	Nine Months Ended September 30, 2013
	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	—			—			—			—			—
Other	—			(17,176		)	9,276			17,176			9,276
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
The Company revised its condensed consolidating balance sheet as of December 31, 2013 to properly reflect balance sheet positions of the Company's tax-paying entities and to conform with the current period's financial statement presentation. Specifically, other assets and deferred income taxes of non-guarantor subsidiaries each increased by $24.7 million at December 31, 2013. Additionally, prepaid expenses and other current assets of non-guarantor subsidiaries increased by $7.1 million, with a corresponding increase in other current liabilities of non-guarantor subsidiaries of $7.1 million at December 31, 2013.
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.

ACCOUNTING_POLICIES_Policies

ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2014
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 2013 Annual Report on Form 10-K filed with the SEC. The December 31, 2013 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, 2014, the unaudited condensed consolidated statements of income and comprehensive income for the three and nine months ended September 30, 2014 and 2013, respectively, and the unaudited condensed consolidated statements of cash flows for the nine months ended September 30, 2014 and 2013, 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	'
	Revision
	Certain amounts in the Company's consolidated balance sheet as of December 31, 2013, as presented herein, have been revised to appropriately present current and non-current deferred tax balances as well as current taxes refundable/payable in accordance with ASC 740, "Income Taxes".
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, 2014, the carrying value of WESCO’s 6.0% Convertible Senior Debentures due 2029 (the "2029 Debentures") was $176.7 million and the fair value was approximately $1.0 billion. At December 31, 2013, the carrying value of WESCO’s 2029 Debentures was $174.1 million and the fair value was approximately $1.1 billion. 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, 2014
Business Combinations [Abstract]	'
Business Acquisition, Pro Forma Information [Table Text Block]	'

STOCKBASED_COMPENSATION_Tables

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2014
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, 2014 and 2013, WESCO granted the following stock-settled stock appreciation rights, restricted stock units and performance-based awards at the following weighted average fair values and assumptions:
		Three Months Ended								Nine Months Ended
		September 30,				September 30,				September 30,				September 30,
		2014				2013				2014				2013
	Stock-settled appreciation rights granted	—				900				274,508				252,473
	Weighted average fair value	$	—			$	32.05			$	30.64			$	31.33
	Restricted stock units granted	611				—				63,117				69,393
	Weighted average fair value	$	81.88			$	—			$	85.32			$	72.15
	Performance-based awards granted	—				—				44,046				48,058
	Weighted average fair value	$	—			$	—			$	86.65			$	78.21
	Risk free interest rate	—		%		1.6		%		1.5		%		0.9		%
	Expected life (in years)	0				5				5				5
	Expected volatility	—		%		48		%		39		%		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, 2014:
		Awards			Weighted				Weighted			Aggregate
					Average				Average			Intrinsic
					Exercise				Remaining			Value
					Price				Contractual Term (In Years)			(In thousands)
	Outstanding at December 31, 2013	2,715,651			$	45.93
	Granted	274,508			85.35
	Exercised	(452,795	)		40.8
	Forfeited	(20,375	)		70.86
	Outstanding at September 30, 2014	2,516,989			50.95				5.5			$	70,664
	Exercisable at September 30, 2014	2,013,895			$	44.18			4.7			$	68,633
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, 2014:
		Awards			Weighted
					Average
					Fair
					Value
	Unvested at December 31, 2013	184,746			$	66.08
	Granted	63,117			85.32
	Vested	(51,287	)		60.85
	Forfeited	(9,620	)		68.9
	Unvested at September 30, 2014	186,956			$	73.86
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, 2014:
		Awards			Weighted
					Average
					Fair
					Value
	Unvested at December 31, 2013	92,484			$	76.98
	Granted	44,046			86.65
	Vested	—			—
	Forfeited	(6,526	)		77.87
	Unvested at September 30, 2014	130,004			$	80.21
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, 2014 was estimated using the following weighted-average assumptions:
	Weighted Average Assumptions
	Grant date share price	$	86.65
	WESCO expected volatility	35.4		%
	Peer group median volatility	28.7		%
	Risk-free interest rate	0.62		%
	Correlation	103.1		%

EARNINGS_PER_SHARE_Tables

EARNINGS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2014
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,
	Amounts in thousands, except per share data	2014		2013
	Net income attributable to WESCO International, Inc.	$	80,816	$	69,162
	Weighted average common shares outstanding used in computing basic earnings per share	44,475		44,180
	Common shares issuable upon exercise of dilutive equity awards	990		1,067
	Common shares issuable from contingently convertible debentures (see below for basis of calculation)	7,778		7,299
	Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	53,243		52,546
	Earnings per share attributable to WESCO International, Inc.
	Basic	$	1.82	$	1.57
	Diluted	$	1.52	$	1.32
		Nine Months Ended
		September 30,
	Amounts in thousands, except per share data	2014		2013
	Net income attributable to WESCO International, Inc.	$	201,523	$	218,436
	Weighted average common shares outstanding used in computing basic earnings per share	44,425		44,127
	Common shares issuable upon exercise of dilutive equity awards	1,036		1,088
	Common shares issuable from contingently convertible debentures (see below for basis of calculation)	7,901		7,214
	Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share	53,362		52,429
	Earnings per share attributable to WESCO International, Inc.
	Basic	$	4.54	$	4.95
	Diluted	$	3.78	$	4.17

EMPLOYEE_BENEFIT_PLANS_Schedul

EMPLOYEE BENEFIT PLANS Schedule of Net Benefit Costs (Tables)	9 Months Ended
	Sep. 30, 2014
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, 2014 and 2013:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
	Amounts in thousands	2014			2013			2014			2013
	Service cost	$	912		$	996		$	2,712		$	3,049
	Interest cost	1,172			1,117			3,486			3,422
	Expected return on plan assets	(1,380		)	(1,173		)	(4,103		)	(3,081		)
	Net periodic benefit cost	$	704		$	940		$	2,095		$	3,390

OTHER_FINANCIAL_INFORMATION_Ta

OTHER FINANCIAL INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2014
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)
	Amounts in thousands	September 30, 2014
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Cash and cash equivalents	$	—		$	37,639		$	72,729		$	—		$	110,368
	Trade accounts receivable, net	—			—			1,218,759			—			1,218,759
	Inventories, net	—			380,584			465,582			—			846,166
	Other current assets	18			172,936			145,653			(43,863		)	274,744
	Total current assets	18			591,159			1,902,723			(43,863		)	2,450,037
	Intercompany receivables, net	—			—			1,833,480			(1,833,480		)	—
	Property, buildings and equipment, net	—			57,966			133,427			—			191,393
	Intangible assets, net	—			4,901			447,239			—			452,140
	Goodwill	—			246,771			1,513,062			—			1,759,833
	Investments in affiliates	3,284,749			3,820,458			—			(7,105,207		)	—
	Other noncurrent assets	4,152			13,586			34,327			—			52,065
	Total assets	$	3,288,919		$	4,734,841		$	5,864,258		$	(8,982,550	)	$	4,905,468
	Accounts payable	$	—		$	482,892		$	359,887		$	—		$	842,779
	Short-term debt	—			—			43,006			—			43,006
	Other current liabilities	11,533			114,565			158,661			(43,863		)	240,896
	Total current liabilities	11,533			597,457			561,554			(43,863		)	1,126,681
	Intercompany payables, net	1,174,355			659,125			—			(1,833,480		)	—
	Long-term debt	176,691			680,618			614,465			—			1,471,774
	Other noncurrent liabilities	17,613			234,121			146,634			—			398,368
	Total WESCO International stockholders' equity	1,908,727			2,563,520			4,541,687			(7,105,207		)	1,908,727
	Noncontrolling interest	—			—			(82		)	—			(82		)
	Total liabilities and stockholders’ equity	$	3,288,919		$	4,734,841		$	5,864,258		$	(8,982,550	)	$	4,905,468
	WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
	CONDENSED CONSOLIDATING BALANCE SHEETS
	(unaudited)
	Amounts in thousands	December 31, 2013
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Cash and cash equivalents	$	—		$	31,695		$	92,030		$	—		$	123,725
	Trade accounts receivable, net	—			—			1,045,054			—			1,045,054
	Inventories, net	—			351,242			436,082			—			787,324
	Other current assets	22			166,540			127,439			(44,489		)	249,512
	Total current assets	22			549,477			1,700,605			(44,489		)	2,205,615
	Intercompany receivables, net	—			—			1,906,785			(1,906,785		)	—
	Property, buildings and equipment, net	—			59,569			139,085			—			198,654
	Intangible assets, net	—			5,404			433,763			—			439,167
	Goodwill	—			246,125			1,488,266			—			1,734,391
	Investments in affiliates	3,137,418			3,722,902			—			(6,860,320		)	—
	Other noncurrent assets	4,361			15,627			51,078			—			71,066
	Total assets	$	3,141,801		$	4,599,104		$	5,719,582		$	(8,811,594	)	$	4,648,893
	Accounts payable	$	—		$	410,017		$	325,080		$	—		$	735,097
	Short-term debt	—			—			37,551			—			37,551
	Other current liabilities	11,920			114,894			196,690			(44,489		)	279,015
	Total current liabilities	11,920			524,911			559,321			(44,489		)	1,051,663
	Intercompany payables, net	1,168,507			738,278			—			(1,906,785		)	—
	Long-term debt	174,149			675,424			598,061			—			1,447,634
	Other noncurrent liabilities	22,416			220,650			141,739			—			384,805
	Total WESCO International stockholders' equity	1,764,809			2,439,841			4,420,479			(6,860,320		)	1,764,809
	Noncontrolling interest	—			—			(18		)	—			(18		)
	Total liabilities and stockholders’ equity	$	3,141,801		$	4,599,104		$	5,719,582		$	(8,811,594	)	$	4,648,893
Condensed Financial Information Statement Of Income [Text Block]	'
	Amounts in thousands	Three Months Ended September 30, 2014
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Net sales	$	—		$	932,948		$	1,174,935		$	(29,733	)	$	2,078,150
	Cost of goods sold	—			747,219			938,301			(29,733		)	1,655,787
	Selling, general and administrative expenses	—			141,924			129,773			—			271,697
	Depreciation and amortization	—			4,670			12,748			—			17,418
	Results of affiliates’ operations	85,219			62,611			—			(147,830		)	—
	Interest expense, net	6,123			18,765			(4,090		)	—			20,798
	Provision for income taxes	(1,722		)	5,733			27,621			—			31,632
	Net income	80,818			77,248			70,582			(147,830		)	80,818
	Less: Net loss attributable to noncontrolling interest	—			—			2			—			2
	Net income attributable to WESCO International, Inc.	$	80,818		$	77,248		$	70,580		$	(147,830	)	$	80,816
	Comprehensive income:
	Foreign currency translation adjustment	(63,794		)	(63,794		)	(63,794		)	127,588			(63,794		)
	Comprehensive income attributable to WESCO International, Inc.	$	17,024		$	13,454		$	6,786		$	(20,242	)	$	17,022
	Amounts in thousands	Three Months Ended September 30, 2013
		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	69,118			65,595			66,220			(131,815		)	69,118
	Less: Net income attributable to noncontrolling interest	—			—			(44		)	—			(44		)
	Net income 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
	WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENTS OF INCOME AND COMPREHENSIVE INCOME
	(unaudited)
	Amounts in thousands	Nine Months Ended September 30, 2014
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and
		Inc.			Inc.						Eliminating
											Entries
	Net sales	$	—		$	2,656,619		$	3,323,237		$	(85,715	)	$	5,894,141
	Cost of goods sold	—			2,126,743			2,644,229			(85,715		)	4,685,257
	Selling, general and administrative expenses	2			423,371			392,496			—			815,869
	Depreciation and amortization	—			14,284			36,692			—			50,976
	Results of affiliates’ operations	214,601			164,826			—			(379,427		)	—
	Interest expense, net	18,277			55,854			(12,308		)	—			61,823
	Provision for income taxes	(5,137		)	10,244			73,650			—			78,757
	Net income	201,459			190,949			188,478			(379,427		)	201,459
	Less: Net income attributable to noncontrolling interest	—			—			(64		)	—			(64		)
	Net income attributable to WESCO International, Inc.	$	201,459		$	190,949		$	188,542		$	(379,427	)	$	201,523
	Comprehensive income:
	Foreign currency translation adjustment	(67,271		)	(67,271		)	(67,271		)	134,542			(67,271		)
	Comprehensive income attributable to WESCO International, Inc.	$	134,188		$	123,678		$	121,271		$	(244,885	)	$	134,252
	Amounts in thousands	Nine Months Ended September 30, 2013
		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	231,482			157,726			—			(389,208		)	—
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	(4,997		)	34,617			54,947			—			84,567
Net income	218,562			208,794			180,414			(389,208		)	218,562
Less: Net income attributable to noncontrolling interest	—			—			126			—			126
Net income attributable to WESCO International, Inc.	$	218,562		$	208,794		$	180,288		$	(389,208	)	$	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		$	137,077		$	(302,786	)	$	175,225
Condensed Financial Information Statements Of Cash Flows [Text Block]	'
	Amounts in thousands	Nine Months Ended September 30, 2014
		WESCO			WESCO			Non-Guarantor			Consolidating			Consolidated
		International,			Distribution,			Subsidiaries			and Eliminating
		Inc.			Inc.						Entries
	Net cash (used) provided by operating activities	$	(5,202	)	$	68,291		$	76,731		$	—		$	139,820
	Investing activities:
	Capital expenditures	—			(10,811		)	(5,225		)	—			(16,036		)
	Acquisition payments	—			(42,132		)	(96,673		)	—			(138,805		)
	Other	—			(5,842		)	5,444			5,842			5,444
	Net cash used in investing activities	—			(58,785		)	(96,454		)	5,842			(149,397		)
	Financing activities:
	Borrowings	6,517			645,411			316,462			(6,517		)	961,873
	Repayments	(675		)	(640,411		)	(316,560		)	675			(956,971		)
	Other	(640		)	(8,562		)	(110		)	—			(9,312		)
	Net cash provided (used) by financing activities	5,202			(3,562		)	(208		)	(5,842		)	(4,410		)
	Effect of exchange rate changes on cash and cash equivalents	—			—			630			—			630
	Net change in cash and cash equivalents	—			5,944			(19,301		)	—			(13,357		)
	Cash and cash equivalents at the beginning of year	—			31,695			92,030			—			123,725
	Cash and cash equivalents at the end of period	$	—		$	37,639		$	72,729		$	—		$	110,368
	WESCO INTERNATIONAL, INC. AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS
	(unaudited)
	Amounts in thousands	Nine Months Ended September 30, 2013
		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	—			—			—			—			—
	Other	—			(17,176		)	9,276			17,176			9,276
	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

ORGANIZATION_Details

ORGANIZATION (Details)	9 Months Ended
	Sep. 30, 2014
	customers
	distribution_centers
	countries
	branches
Restructuring Cost and Reserve [Line Items]	'
Active customers (in customers)	75,000
Full service branches (in branches)	475
Distribution centers (in distribution centers)	9
Additional countries (in countries)	15
Hazmasters, Inc. [Member]	'
Restructuring Cost and Reserve [Line Items]	'
Full service branches (in branches)	14

ACCOUNTING_POLICIES_Details

ACCOUNTING POLICIES (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Accounting Policies [Abstract]	'	'
Fixed Rate Debt, Par Value	$176.70	$174.10
Fixed Rate Debt, Fair Value Disclosures	$957.10	$1,124.30

ACQUISITIONS_ACQUISITIONS_Deta

ACQUISITIONS - ACQUISITIONS (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Business Acquisition [Line Items]	'
Fair Value of Assets Acquired	$153,430,000
Noncash or Part Noncash Acquisition, Value of Liabilities Assumed	14,625,000
Payments to Acquire Businesses, Gross	138,805,000
Finite-lived Intangible Assets Acquired	300,000
Customer Relationships	40,000,000
Supplier Relationships (Intangible Assets)	3,200,000
Trademarks	12,100,000
LaPrairie, Inc. [Member]	'
Business Acquisition [Line Items]	'
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period	30,000,000
Finite-lived Intangible Assets Acquired	11,000,000
Goodwill, Acquired During Period	8,900,000
Hazmasters, Inc. [Member]	'
Business Acquisition [Line Items]	'
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period	80,000,000
Finite-lived Intangible Assets Acquired	28,100,000
Goodwill, Acquired During Period	29,100,000
Hi-Line [Member]	'
Business Acquisition [Line Items]	'
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period	30,000,000
Finite-lived Intangible Assets Acquired	16,500,000
Goodwill, Acquired During Period	$21,600,000

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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement By Share-based Payment Award, Options and Stock Appreciation Rights, Outstanding [Roll Forward]	'	'	'	'
Beginning of Year (in shares)	'	'	2,715,651	'
Grants in Period (in shares)	'	'	274,508	'
Exercises in Period (in shares)	'	'	452,795	'
Forfeitures in Period (in shares)	'	'	20,375	'
End of Period (in shares)	2,516,989	'	2,516,989	'
Exercisable (in shares)	2,013,895	'	2,013,895	'
Weighted Average Exercise Price, Beginning of Year (in dollars per share)	'	'	$45.93	'
Weighted Average Exercise Price, Grants in Period (in dollars per share)	'	'	$85.35	'
Weighted Average Exercise Price, Exercises in Period (in dollars per share)	'	'	$40.80	'
Weighted Average Exercise Price, Forfeitures in Period (in dollars per share)	'	'	$70.86	'
Weighted Average Exercise Price, End of Period (in dollars per share)	$50.95	'	$50.95	'
Weighted Average Exercise Price, Exercisable (in dollars per share)	$44.18	'	$44.18	'
Weighted Average Remaining Contractual Term, Outstanding (in years)	5.5	'	5.5	'
Weighted Average Remaining Contractual Term, Exercisable (in years)	4.7	'	4.7	'
Aggregate Intrinsic Value, Outstanding	$70,664	'	$70,664	'
Aggregate Intrinsic Value, Exercisable	$68,633	'	$68,633	'
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	$0	$32.05	$30.64	$31.33

SCHEDULE_OF_SHAREBASED_PAYMENT

SCHEDULE OF SHARE-BASED PAYMENT AWARD, VALUATION ASSUMPTIONS (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Risk free interest rate	0.00%	1.60%	1.50%	0.90%
Expected life (in years)	'0 years	'5 years	'5 years	'5 years
WESCO expected volatility	0.00%	48.00%	39.00%	50.00%
Stock Appreciation Rights (SARs) [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Granted (in shares)	0	900	274,508	252,473
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	0	32.05	30.64	31.33
Restricted Stock Units (RSUs) [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Granted (in shares)	611	0	63,117	69,393
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	81.88	0	85.32	72.15
Performance-based Awards [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Granted (in shares)	0	0	44,046	48,058
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	0	0	86.65	78.21

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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
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)	186,956	'	186,956	'	184,746
Granted (in shares)	611	0	63,117	69,393	'
Vested (in shares)	'	'	-51,287	'	'
Forfeited (in shares)	'	'	-9,620	'	'
Unvested, Weighted Average Fair Value (in dollars per share)	$73.86	'	$73.86	'	$66.08
Granted, Weighted Average Fair Value (in dollars per share)	$81.88	$0	$85.32	$72.15	'
Vested in Period, Weighted Average Fair Value (in dollars per share)	'	'	$60.85	'	'
Forfeited in Period, Weighted Average Fair Value (in dollars per share)	'	'	$68.90	'	'

SUMMARY_OF_PERFORMANCEBASED_AW

SUMMARY OF PERFORMANCE-BASED AWARDS (Details) (Performance-based Awards [Member], USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Performance-based Awards [Member]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]	'	'	'	'	'
Unvested (in shares)	130,004	'	130,004	'	92,484
Granted (in shares)	0	0	44,046	48,058	'
Vested (in shares)	'	'	0	'	'
Forfeited (in shares)	'	'	-6,526	'	'
Unvested, Weighted Average Fair Value (in dollars per share)	$80.21	'	$80.21	'	$76.98
Granted, Weighted Average Fair Value (in dollars per share)	$0	$0	$86.65	$78.21	'
Vested in Period, Weighted Average Fair Value (in dollars per share)	'	'	$0	'	'
Forfeited in Period, Weighted Average Fair Value (in dollars per share)	'	'	$77.87	'	'

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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
WESCO expected volatility	0.00%	48.00%	39.00%	50.00%
Risk free interest rate	0.00%	1.60%	1.50%	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	'	'	86.65	'
WESCO expected volatility	'	'	35.40%	'
Peer group mean volatility	'	'	28.70%	'
Risk free interest rate	'	'	0.62%	'
Correlation	'	'	103.10%	'

STOCKBASED_COMPENSATION_Detail

STOCK-BASED COMPENSATION (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Stock-based compensation expense	$2.50	$3.70	$11	$12.50	'
Total unrecognized compensation cost	20.9	'	20.9	'	'
Compensation cost expected to be recognized over the remainder of 2014	'	'	3.8	'	'
Compensation cost expected to be recognized in 2015	'	'	10.6	'	'
Compensation cost expected to be recognized in 2016	'	'	5.8	'	'
Compensation cost expected to be recognized in 2017	'	'	0.7	'	'
Total intrinsic value of awards exercised	'	'	24.2	14.1	'
Cash received from exercise of options	'	'	0.8	0.1	'
Tax benefit associated with exercise of awards	'	'	$9.10	$4.80	'
Stock Appreciation Rights (SARs) [Member]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Granted, Weighted Average Fair Value (in dollars per share)	$0	$32.05	$30.64	$31.33	'
Restricted Stock Units (RSUs) [Member]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Granted, Weighted Average Fair Value (in dollars per share)	$81.88	$0	$85.32	$72.15	'
Performance-based awards outstanding (in shares)	186,956	'	186,956	'	184,746
Performance-based Awards [Member]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Granted, Weighted Average Fair Value (in dollars per share)	$0	$0	$86.65	$78.21	'
Performance-based awards outstanding (in shares)	130,004	'	130,004	'	92,484
Performance-based Awards - Peer Group Total Shareholder Return [Member]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Performance-based awards outstanding (in shares)	65,002	'	65,002	'	'

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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net income (loss) attributable to WESCO International, Inc.	$80,816	$69,162	$201,523	$218,436
Weighted average common shares outstanding used in computing basic earnings per share (in shares)	44,475,000	44,180,000	44,425,000	44,127,000
Common shares issuable upon exercise of dilutive stock options (in shares)	990,000	1,067,000	1,036,000	1,088,000
Common shares issuable from contingently convertible debentures (in shares)	7,778,000	7,299,000	7,901,000	7,214,000
Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share (in shares)	53,243,000	52,546,000	53,362,000	52,429,000
Earnings Per Share, Basic and Diluted [Abstract]	'	'	'	'
Basic (in dollars per share)	$1.82	$1.57	$4.54	$4.95
Diluted (in dollars per share)	$1.52	$1.32	$3.78	$4.17

EARNINGS_PER_SHARE_Details

EARNINGS PER SHARE (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
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	300,000	500,000	500,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Weighted Average Exercise Price (in dollars per share)	$84.47	$71.81	$79.29	$65.29
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)	$0.26	$0.21	$0.65	$0.66
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)	'	'	11,948,374	'

EMPLOYEE_BENEFIT_PLANS_Details

EMPLOYEE BENEFIT PLANS (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Compensation and Retirement Disclosure [Abstract]	'	'	'	'
Defined Benefit Plan, Contributions by Employer	$500,000	$22,100,000	$1,700,000	$23,900,000
Schedule of Employee Benefit Plans [Line Items]	'	'	'	'
Defined Contribution Plan, Cost Recognized	'	'	$23,300,000	$25,700,000
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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Compensation and Retirement Disclosure [Abstract]	'	'	'	'
Defined Benefit Plan, Contributions by Employer	$500,000	$22,100,000	$1,700,000	$23,900,000
Service cost	912,000	996,000	2,712,000	3,049,000
Interest cost	1,172,000	1,117,000	3,486,000	3,422,000
Expected return on plan assets	-1,380,000	-1,173,000	-4,103,000	-3,081,000
Net periodic benefit cost	$704,000	$940,000	$2,095,000	$3,390,000

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Details) (USD $)	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'	'
Damages sought	'	$50
Damages awarded	'	36.1
Prejudgment interest awarded	'	3.9
Post-judgment interest awarded	$8.70	'

INCOME_TAXES_Details

INCOME TAXES (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2013
Income Tax Contingency [Line Items]	'	'	'
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	$4.80	'	'
Effective tax rate	28.10%	30.90%	27.90%
Federal statutory rate	35.00%	'	'

OTHER_FINANCIAL_INFORMATION_De

OTHER FINANCIAL INFORMATION (Details) (USD $)	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified		Convertible Senior Debentures Due in 2029 [Member]	Senior Notes due 2021 [Member]	Non-Guarantor Subsidiaries [Member]
Debt Instrument [Line Items]	'	'	'	'
Change in presentation of other assets and deferred income taxes	'	'	'	$24.70
Change in presentation of other current assets and other current liabilities	'	'	'	7.1
Debt Instrument, Face Amount	'	$344.90	$500	'
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.38%	'	'	'

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Mar. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Condensed Financial Information [Line Items]	'	'	'	'	'
Cash and cash equivalents	$110,368	$123,725	$98,575	$98,575	$86,099
Trade accounts receivable, net	1,218,759	1,045,054	'	'	'
Inventories, net	846,166	787,324	'	'	'
Other current assets	274,744	249,512	'	'	'
Total current assets	2,450,037	2,205,615	'	'	'
Intercompany receivables, net	0	0	'	'	'
Property, buildings and equipment, net	191,393	198,654	'	'	'
Intangible assets, net	452,140	439,167	'	'	'
Goodwill and other intangibles, net	1,759,833	1,734,391	'	'	'
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0	'	'	'
Other assets	52,065	71,066	'	'	'
Total assets	4,905,468	4,648,893	'	'	'
Accounts payable	842,779	735,097	'	'	'
Short-term debt	43,006	37,551	'	'	'
Other current liabilities	240,896	279,015	'	'	'
Total current liabilities	1,126,681	1,051,663	'	'	'
Intercompany payables, net	0	0	'	'	'
Long-term debt	1,471,774	1,447,634	'	'	'
Other noncurrent liabilities	398,368	384,805	'	'	'
Total stockholders' equity	1,908,727	1,764,809	'	'	'
Stockholders' Equity Attributable to Noncontrolling Interest	82	18	'	'	'
Total liabilities and stockholders' equity	4,905,468	4,648,893	'	'	'
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	18	22	'	'	'
Total current assets	18	22	'	'	'
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	3,284,749	3,137,418	'	'	'
Other assets	4,152	4,361	'	'	'
Total assets	3,288,919	3,141,801	'	'	'
Accounts payable	0	0	'	'	'
Short-term debt	0	0	'	'	'
Other current liabilities	11,533	11,920	'	'	'
Total current liabilities	11,533	11,920	'	'	'
Intercompany payables, net	1,174,355	1,168,507	'	'	'
Long-term debt	176,691	174,149	'	'	'
Other noncurrent liabilities	17,613	22,416	'	'	'
Total stockholders' equity	1,908,727	1,764,809	'	'	'
Stockholders' Equity Attributable to Noncontrolling Interest	0	0	'	'	'
Total liabilities and stockholders' equity	3,288,919	3,141,801	'	'	'
WESCO Distribution, Inc.	'	'	'	'	'
Condensed Financial Information [Line Items]	'	'	'	'	'
Cash and cash equivalents	37,639	31,695	45,838	'	52,275
Trade accounts receivable, net	0	0	'	'	'
Inventories, net	380,584	351,242	'	'	'
Other current assets	172,936	166,540	'	'	'
Total current assets	591,159	549,477	'	'	'
Intercompany receivables, net	0	0	'	'	'
Property, buildings and equipment, net	57,966	59,569	'	'	'
Intangible assets, net	4,901	5,404	'	'	'
Goodwill and other intangibles, net	246,771	246,125	'	'	'
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	3,820,458	3,722,902	'	'	'
Other assets	13,586	15,627	'	'	'
Total assets	4,734,841	4,599,104	'	'	'
Accounts payable	482,892	410,017	'	'	'
Short-term debt	0	0	'	'	'
Other current liabilities	114,565	114,894	'	'	'
Total current liabilities	597,457	524,911	'	'	'
Intercompany payables, net	659,125	738,278	'	'	'
Long-term debt	680,618	675,424	'	'	'
Other noncurrent liabilities	234,121	220,650	'	'	'
Total stockholders' equity	2,563,520	2,439,841	'	'	'
Stockholders' Equity Attributable to Noncontrolling Interest	0	0	'	'	'
Total liabilities and stockholders' equity	4,734,841	4,599,104	'	'	'
Non-Guarantor Subsidiaries [Member]	'	'	'	'	'
Condensed Financial Information [Line Items]	'	'	'	'	'
Cash and cash equivalents	72,729	92,030	52,737	'	33,824
Trade accounts receivable, net	1,218,759	1,045,054	'	'	'
Inventories, net	465,582	436,082	'	'	'
Other current assets	145,653	127,439	'	'	'
Total current assets	1,902,723	1,700,605	'	'	'
Intercompany receivables, net	1,833,480	1,906,785	'	'	'
Property, buildings and equipment, net	133,427	139,085	'	'	'
Intangible assets, net	447,239	433,763	'	'	'
Goodwill and other intangibles, net	1,513,062	1,488,266	'	'	'
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0	'	'	'
Other assets	34,327	51,078	'	'	'
Total assets	5,864,258	5,719,582	'	'	'
Accounts payable	359,887	325,080	'	'	'
Short-term debt	43,006	37,551	'	'	'
Other current liabilities	158,661	196,690	'	'	'
Total current liabilities	561,554	559,321	'	'	'
Intercompany payables, net	0	0	'	'	'
Long-term debt	614,465	598,061	'	'	'
Other noncurrent liabilities	146,634	141,739	'	'	'
Total stockholders' equity	4,541,687	4,420,479	'	'	'
Stockholders' Equity Attributable to Noncontrolling Interest	82	18	'	'	'
Total liabilities and stockholders' equity	5,864,258	5,719,582	'	'	'
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	-43,863	-44,489	'	'	'
Total current assets	-43,863	-44,489	'	'	'
Intercompany receivables, net	-1,833,480	-1,906,785	'	'	'
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	-7,105,207	-6,860,320	'	'	'
Other assets	0	0	'	'	'
Total assets	-8,982,550	-8,811,594	'	'	'
Accounts payable	0	0	'	'	'
Short-term debt	0	0	'	'	'
Other current liabilities	-43,863	-44,489	'	'	'
Total current liabilities	-43,863	-44,489	'	'	'
Intercompany payables, net	-1,833,480	-1,906,785	'	'	'
Long-term debt	0	0	'	'	'
Other noncurrent liabilities	0	0	'	'	'
Total stockholders' equity	-7,105,207	-6,860,320	'	'	'
Stockholders' Equity Attributable to Noncontrolling Interest	0	0	'	'	'
Total liabilities and stockholders' equity	($8,982,550)	($8,811,594)	'	'	'

CONDENSED_CONSOLIDATED_INCOME_

CONDENSED CONSOLIDATED INCOME STATEMENTS (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Condensed Financial Information [Line Items]	'	'	'	'
Net sales	$2,078,150,000	$1,931,260,000	$5,894,141,000	$5,633,271,000
Cost of goods sold	1,655,787,000	1,535,609,000	4,685,257,000	4,463,991,000
Selling, general and administrative expense	271,697,000	255,202,000	815,869,000	748,164,000
Depreciation and amortization	17,418,000	16,803,000	50,976,000	50,673,000
Results of affiliates' operations	0	0	0	0
Interest expense, net	20,798,000	21,304,000	61,823,000	64,999,000
Gain (Loss) on Disposition of Business	'	2,315,000	'	2,315,000
Provision for income taxes	31,632,000	30,909,000	78,757,000	84,567,000
Net income (loss)	80,818,000	69,118,000	201,459,000	218,562,000
Less: Net (loss) income attributable to noncontrolling interest	2,000	-44,000	-64,000	126,000
Net income (loss) attributable to WESCO International, Inc.	80,816,000	69,162,000	201,523,000	218,436,000
Comprehensive Income:	'	'	'	'
Foreign currency translation adjustment	-63,794,000	24,619,000	-67,271,000	-43,211,000
Comprehensive income attributable to WESCO International, Inc.	17,022,000	93,781,000	134,252,000	175,225,000
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	0	19,000	2,000	24,000
Depreciation and amortization	0	0	0	0
Results of affiliates' operations	85,219,000	73,241,000	214,601,000	231,482,000
Interest expense, net	6,123,000	5,944,000	18,277,000	17,893,000
Gain (Loss) on Disposition of Business	'	0	'	0
Provision for income taxes	-1,722,000	-1,840,000	-5,137,000	-4,997,000
Net income (loss)	80,818,000	69,118,000	201,459,000	218,562,000
Less: Net (loss) income attributable to noncontrolling interest	0	0	0	0
Net income (loss) attributable to WESCO International, Inc.	80,818,000	69,118,000	201,459,000	218,562,000
Comprehensive Income:	'	'	'	'
Foreign currency translation adjustment	-63,794,000	24,619,000	-67,271,000	-43,211,000
Comprehensive income attributable to WESCO International, Inc.	17,024,000	93,737,000	134,188,000	175,351,000
Guarantor Subsidiaries [Member]	'	'	'	'
Condensed Financial Information [Line Items]	'	'	'	'
Net sales	'	'	2,656,619,000	2,572,693,000
Cost of goods sold	'	'	2,126,743,000	2,047,937,000
Selling, general and administrative expense	'	'	423,371,000	368,853,000
Depreciation and amortization	'	'	14,284,000	13,551,000
Results of affiliates' operations	'	'	164,826,000	157,726,000
Interest expense, net	'	'	55,854,000	56,667,000
Gain (Loss) on Disposition of Business	'	'	'	0
Provision for income taxes	'	'	10,244,000	34,617,000
Net income (loss)	'	'	190,949,000	208,794,000
Less: Net (loss) income attributable to noncontrolling interest	'	'	0	0
Net income (loss) attributable to WESCO International, Inc.	'	'	190,949,000	208,794,000
Comprehensive Income:	'	'	'	'
Foreign currency translation adjustment	'	'	-67,271,000	-43,211,000
Comprehensive income attributable to WESCO International, Inc.	'	'	123,678,000	165,583,000
WESCO Distribution, Inc.	'	'	'	'
Condensed Financial Information [Line Items]	'	'	'	'
Net sales	932,948,000	878,851,000	'	'
Cost of goods sold	747,219,000	698,965,000	'	'
Selling, general and administrative expense	141,924,000	129,518,000	'	'
Depreciation and amortization	4,670,000	4,668,000	'	'
Results of affiliates' operations	62,611,000	58,574,000	'	'
Interest expense, net	18,765,000	18,823,000	'	'
Gain (Loss) on Disposition of Business	'	0	'	'
Provision for income taxes	5,733,000	19,856,000	'	'
Net income (loss)	77,248,000	65,595,000	'	'
Less: Net (loss) income attributable to noncontrolling interest	0	0	'	'
Net income (loss) attributable to WESCO International, Inc.	77,248,000	65,595,000	'	'
Comprehensive Income:	'	'	'	'
Foreign currency translation adjustment	-63,794,000	24,619,000	'	'
Comprehensive income attributable to WESCO International, Inc.	13,454,000	90,214,000	'	'
Non-Guarantor Subsidiaries [Member]	'	'	'	'
Condensed Financial Information [Line Items]	'	'	'	'
Net sales	1,174,935,000	1,082,585,000	3,323,237,000	3,154,350,000
Cost of goods sold	938,301,000	866,820,000	2,644,229,000	2,509,826,000
Selling, general and administrative expense	129,773,000	125,665,000	392,496,000	379,287,000
Depreciation and amortization	12,748,000	12,135,000	36,692,000	37,122,000
Results of affiliates' operations	0	0	0	0
Interest expense, net	-4,090,000	-3,463,000	-12,308,000	-9,561,000
Gain (Loss) on Disposition of Business	'	2,315,000	'	2,315,000
Provision for income taxes	27,621,000	12,893,000	73,650,000	54,947,000
Net income (loss)	70,582,000	66,220,000	188,478,000	180,414,000
Less: Net (loss) income attributable to noncontrolling interest	2,000	-44,000	-64,000	126,000
Net income (loss) attributable to WESCO International, Inc.	70,580,000	66,264,000	188,542,000	180,288,000
Comprehensive Income:	'	'	'	'
Foreign currency translation adjustment	-63,794,000	24,619,000	-67,271,000	-43,211,000
Comprehensive income attributable to WESCO International, Inc.	6,786,000	90,883,000	121,271,000	137,077,000
Consolidation, Eliminations [Member]	'	'	'	'
Condensed Financial Information [Line Items]	'	'	'	'
Net sales	-29,733,000	-30,176,000	-85,715,000	-93,772,000
Cost of goods sold	-29,733,000	-30,176,000	-85,715,000	-93,772,000
Selling, general and administrative expense	0	0	0	0
Depreciation and amortization	0	0	0	0
Results of affiliates' operations	-147,830,000	-131,815,000	-379,427,000	-389,208,000
Interest expense, net	0	0	0	0
Gain (Loss) on Disposition of Business	'	0	'	0
Provision for income taxes	0	0	0	0
Net income (loss)	-147,830,000	-131,815,000	-379,427,000	-389,208,000
Less: Net (loss) income attributable to noncontrolling interest	0	0	0	0
Net income (loss) attributable to WESCO International, Inc.	-147,830,000	-131,815,000	-379,427,000	-389,208,000
Comprehensive Income:	'	'	'	'
Foreign currency translation adjustment	127,588,000	-49,238,000	134,542,000	86,422,000
Comprehensive income attributable to WESCO International, Inc.	($20,242,000)	($181,053,000)	($244,885,000)	($302,786,000)

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Condensed Financial Information [Line Items]	'	'
Net cash (used) provided by operating activities	$139,820	$179,669
Investing Activities:	'	'
Capital expenditures	-16,036	-20,472
Acquisition payments	-138,805	0
Other	5,444	9,276
Net cash used in investing activities	-149,397	-11,196
Financing Activities:	'	'
Borrowings	961,873	802,442
Repayments	-956,971	-949,370
Condensed Proceeds from (Payments for) Other Financing Activities	-9,312	-7,592
Net cash used in financing activities	-4,410	-154,520
Effect of exchange rate changes on cash and cash equivalents	630	-1,477
Net change in cash and cash equivalents	-13,357	12,476
Cash and cash equivalents at the beginning of period	123,725	86,099
Cash and cash equivalents at the end of period	110,368	98,575
Parent Company [Member]	'	'
Condensed Financial Information [Line Items]	'	'
Net cash (used) provided by operating activities	-5,202	-14,515
Investing Activities:	'	'
Capital expenditures	0	0
Acquisition payments	0	0
Other	0	0
Net cash used in investing activities	0	0
Financing Activities:	'	'
Borrowings	6,517	17,176
Repayments	675	0
Condensed Proceeds from (Payments for) Other Financing Activities	-640	-2,661
Net cash used in financing activities	5,202	14,515
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
WESCO Distribution, Inc.	'	'
Condensed Financial Information [Line Items]	'	'
Net cash (used) provided by operating activities	68,291	163,190
Investing Activities:	'	'
Capital expenditures	-10,811	-16,421
Acquisition payments	-42,132	0
Other	-5,842	-17,176
Net cash used in investing activities	-58,785	-33,597
Financing Activities:	'	'
Borrowings	645,411	508,213
Repayments	-640,411	-640,713
Condensed Proceeds from (Payments for) Other Financing Activities	-8,562	-3,530
Net cash used in financing activities	-3,562	-136,030
Effect of exchange rate changes on cash and cash equivalents	0	0
Net change in cash and cash equivalents	5,944	-6,437
Cash and cash equivalents at the beginning of period	31,695	52,275
Cash and cash equivalents at the end of period	37,639	45,838
Non-Guarantor Subsidiaries [Member]	'	'
Condensed Financial Information [Line Items]	'	'
Net cash (used) provided by operating activities	76,731	30,994
Investing Activities:	'	'
Capital expenditures	-5,225	-4,051
Acquisition payments	-96,673	0
Other	5,444	9,276
Net cash used in investing activities	-96,454	5,225
Financing Activities:	'	'
Borrowings	316,462	294,229
Repayments	-316,560	-308,657
Condensed Proceeds from (Payments for) Other Financing Activities	-110	-1,401
Net cash used in financing activities	-208	-15,829
Effect of exchange rate changes on cash and cash equivalents	630	-1,477
Net change in cash and cash equivalents	-19,301	18,913
Cash and cash equivalents at the beginning of period	92,030	33,824
Cash and cash equivalents at the end of period	72,729	52,737
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
Other	5,842	17,176
Net cash used in investing activities	5,842	17,176
Financing Activities:	'	'
Borrowings	-6,517	-17,176
Repayments	-675	0
Condensed Proceeds from (Payments for) Other Financing Activities	0	0
Net cash used in financing activities	-5,842	-17,176
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