WESCO International (WCC) 10-Q 30 Oct 15 2015 Q3 Quarterly report Financial data

DOCUMENT AND ENTITY INFORMATION

DOCUMENT AND ENTITY INFORMATION Document - shares	9 Months Ended
	Sep. 30, 2015	Oct. 29, 2015
Entity [Abstract]
Entity Registrant Name	WESCO INTERNATIONAL INC.
Entity Central Index Key	929,008
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		42,131,220

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2014USD ($)
Depreciation, Depletion and Amortization, Nonproduction	$ 16,287	$ 48,347
Other Accrued Liabilities, Current	136,841	136,841	$ 181,672
Current Assets:
Cash and cash equivalents	132,852	132,852	128,319
Allowance for Doubtful Accounts Receivable, Current	22,513	22,513	21,084
Trade accounts receivable, net of allowance for doubtful accounts of $23,069 and $19,309 in 2014 and 2013, respectively	1,149,743	1,149,743	1,117,420
Accounts and Other Receivables, Net, Current	71,253	71,253	138,745
Inventories, net	844,955	844,955	819,502
Prepaid expenses and other current assets	167,287	167,287	146,352
Total current assets	2,366,090	2,366,090	2,350,338
Property, buildings and equipment, net of accumulated depreciation of $229,041 and $213,758 in 2014 and 2013, respectively	171,789	171,789	182,725
Intangible assets, net	388,988	388,988	429,840
Goodwill	1,666,218	1,666,218	1,735,440
Other assets	49,424	49,424	56,094
Total assets	4,642,509	4,642,509	4,754,437
Current Liabilities:
Accounts payable	787,637	787,637	765,135
Accrued payroll and benefit costs	45,736	45,736	67,935
Short-term debt	44,419	44,419	46,787
Current portion of long-term debt	2,144	2,144	2,343
Total current liabilities	1,016,777	1,016,777	1,063,872
Long-term Debt, Excluding Current Maturities	1,454,705	1,454,705	1,366,430
Other noncurrent liabilities	49,501	49,501	49,227
Deferred income taxes	361,678	361,678	346,743
Total liabilities	$ 2,882,661	$ 2,882,661	$ 2,826,272
Commitments and Contingencies
Stockholders' Equity:
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding	$ 0	$ 0	$ 0
Additional capital	1,114,299	1,114,299	1,102,369
Retained earnings	1,806,052	1,806,052	1,643,914
Treasury stock, at cost; 18,247,467 and 18,179,275 shares in 2014 and 2013, respectively	(772,659)	(772,659)	(616,366)
Accumulated other comprehensive income	(385,526)	(385,526)	(201,892)
Total WESCO International stockholders' equity	1,759,848	1,759,848	1,928,165
Noncontrolling interest	(2,947)	(2,947)	(487)
Total stockholders' equity	1,762,795	1,762,795	1,928,652
Total liabilities and stockholders' equity	4,642,509	4,642,509	4,754,437
Common Stock [Member]
Stockholders' Equity:
Common stock	586	586	584
Common Class B [Member]
Stockholders' Equity:
Common stock	$ 43	$ 43	$ 43

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Allowance for doubtful accounts	$ 22,513,000	$ 21,084,000
Accumulated depreciation	239,604,000	229,196,000
Finite-Lived Intangible Assets, Accumulated Amortization	130,929	110,828
Debt discount	$ 165,714,000	$ 170,367,000
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)	20,762,610	18,250,178
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)	58,587,349	58,400,736
Common stock, shares outstanding (in shares)	42,164,170	44,489,989
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 INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Net sales	$ 1,923,899	$ 2,078,150	$ 5,656,947	$ 5,894,141
Cost of goods sold	1,543,113	1,655,787	4,526,836	4,685,257
Selling, general and administrative expense	258,151	271,697	797,980	815,869
Depreciation and amortization	16,287	17,418	48,347	50,976
Income from operations	106,348	133,248	283,784	342,039
Interest expense, net	20,417	20,798	59,924	61,823
Income before income taxes	85,931	112,450	223,860	280,216
Provision for income taxes	23,547	31,632	64,047	78,757
Net income	62,384	80,818	159,813	201,459
Net (loss) income attributable to noncontrolling interest	(1,119)	2	(2,460)	(64)
Net income attributable to WESCO International, Inc.	63,503	80,816	162,273	201,523
Comprehensive Income:
Foreign currency translation adjustment	(95,377)	(63,794)	(183,634)	(67,271)
Comprehensive income attributable to WESCO International, Inc.	$ (31,874)	$ 17,022	$ (21,361)	$ 134,252
Earnings per share attributable to WESCO International, Inc.
Basic (in dollars per share)	$ 1.47	$ 1.82	$ 3.70	$ 4.54
Diluted (in dollars per share)	$ 1.28	$ 1.52	$ 3.16	$ 3.78

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating Activities:
Net income	$ 159,813	$ 201,459
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	48,347	50,976
Deferred income taxes	26,339	17,847
Other operating activities, net	17,498	4,744
Changes in assets and liabilities
Increase (Decrease) in Accounts Receivable	49,799	174,438
Increase (Decrease) in Accounts and Other Receivables	(64,893)	2,779
Inventories, net	(38,862)	(54,053)
Prepaid expenses and other current assets	(12,052)	(35,097)
Accounts payable	30,389	106,886
Accrued payroll and benefit costs	(20,394)	7,748
Other current and noncurrent liabilities	(50,208)	16,527
Net cash provided by operating activities	175,964	139,820
Investing Activities:
Capital expenditures	(16,242)	(16,036)
Acquisition payments, net of cash acquired	(68,502)	(138,805)
Other investing activities	1,791	5,444
Net cash used in investing activities	(82,953)	(149,397)
Financing Activities:
Proceeds from issuance of short-term debt	75,564	49,727
Repayments of short-term debt	(73,464)	(42,168)
Proceeds from issuance of long-term debt	1,220,334	912,146
Repayments of Long-term Debt	(1,128,694)	(885,408)
Other financing activities, net	(11,253)	(2,381)
Net cash used in financing activities	(73,288)	(4,410)
Payments for Previous Acquisition	0	(29,395)
Payments for Repurchase of Common Stock	(155,775)	(6,931)
Effect of exchange rate on cash and cash equivalents	(15,190)	630
Net change in cash and cash equivalents	4,533	(13,357)
Cash and cash equivalents at the beginning of period	128,319	123,725
Cash and cash equivalents at the end of period	$ 132,852	$ 110,368

ORGANIZATION

ORGANIZATION	9 Months Ended
	Sep. 30, 2015
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 manufacturers (“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. WESCO serves over 75,000 active customers globally, through approximately 485 full service branches and nine distribution centers located primarily in the United States, Canada and Mexico, with operations in 16 additional countries.

ACCOUNTING POLICIES

ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
ACCOUNTING POLICIES	ACCOUNTING POLICIES Basis of Presentation The accompanying 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 information should be read in conjunction with the audited Consolidated Financial Statements and Notes thereto included in WESCO’s 2014 Annual Report on Form 10-K as filed with the SEC on February 24, 2015. The Condensed Consolidated Balance Sheet at December 31, 2014 was derived from the audited Consolidated Financial Statements as of that date, but does not include all of the disclosures required by accounting principles generally accepted in the United States of America. The unaudited Condensed Consolidated Balance Sheet as of September 30, 2015 , the unaudited Condensed Consolidated Statements of Income and Comprehensive Income (Loss) for the three and nine months ended September 30, 2015 and 2014 , respectively, and the unaudited Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2015 and 2014 , 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 presented herein. All adjustments reflected in the unaudited condensed consolidated financial information are of a normal recurring nature unless indicated. The results for the interim periods presented herein are not necessarily indicative of the results to be expected for the full year. The Condensed Consolidated Balance Sheet at December 31, 2014 and the unaudited Condensed Consolidated Statement of Cash Flows for the nine months ended September 30, 2014 include certain reclassifications to previously reported amounts to conform to the current period presentation. Fair Value of Financial Instruments The Company measures the fair value of financial assets and liabilities in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (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 that prioritizes the inputs to valuation techniques used to measure fair value and requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to measurements involving significant unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are as follows: • Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that are accessible at the measurement date. • 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, 2015 , the carrying value of WESCO’s 6.0% Convertible Senior Debentures due 2029 (the "2029 Debentures") was $180.5 million and the fair value was approximately $578.4 million . At December 31, 2014 , the carrying value of WESCO’s 2029 Debentures was $177.6 million and the fair value was approximately $936.1 million . The reported carrying amounts of WESCO’s other debt instruments approximate their fair values. The Company uses a market approach to fair value all of its debt instruments, utilizing quoted prices in active markets, interest rates and other relevant information generated by market transactions involving similar instruments. Therefore, all of the Company's debt instruments are classified as Level 2 within the valuation hierarchy. For all of the Company's remaining financial instruments, consisting of cash and cash equivalents, accounts receivable, accounts payable and other accrued liabilities, carrying values are considered to approximate fair value due to the short maturity of these instruments. New Accounting Pronouncements In June 2014, the FASB issued Accounting Standards Update ("ASU") 2014-12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period . The amendments in this ASU require a reporting entity to treat a performance target that affects vesting and could be achieved after the requisite service period as a performance condition. A reporting entity should apply FASB ASC Topic 718, Compensation — Stock Compensation , to awards with performance conditions that affect vesting. For all entities, ASU 2014-12 is effective for annual periods and interim periods within those annual periods, beginning after December 15, 2015. Early adoption is permitted. This ASU may be adopted either prospectively for share-based payment awards granted or modified on or after the effective date, or retrospectively, using a modified retrospective approach. The modified retrospective approach would apply to share-based payment awards outstanding as of the beginning of the earliest annual period presented in the financial statements on adoption and to all new or modified awards thereafter. The adoption of this guidance is not expected to have a material impact on WESCO's financial position, results of operations or cash flows. In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers: Deferral of Effective Date . The Company previously reported that in May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which 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 ASU 2014-09 is for companies to recognize revenue for 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. ASU 2014-09 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. The amendments in ASU 2015-14 defer the effective date of the new revenue recognition guidance to annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Early adoption is permitted to the original effective date of December 15, 2016, including interim periods within that reporting period. Management is currently evaluating the future impact of this guidance on WESCO's consolidated financial statements and notes thereto. In August 2015, the FASB issued ASU 2015-15, Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements . The Company previously reported that in April 2015, the FASB issued ASU 2015-03, Simplifying the Presentation of Debt Issuance Costs , which simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The amendments in ASU 2015-15 address the absence of authoritative guidance within ASU 2015-03 for debt issuance costs related to line-of-credit arrangements such that the SEC staff would not object to an entity deferring and presenting debt issuance costs as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. ASU 2015-15 and ASU 2015-03 are effective for financial statements of public business entities issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption is permitted for financial statements that have not been previously issued. The adoption of this guidance is not expected to have a material impact on WESCO's financial position, results of operations or cash flows. In September 2015, the FASB issued ASU 2015-16, Business Combinations: Simplifying the Accounting for Measurement-Period Adjustments . The amendments in this ASU require that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined; calculated as if the accounting had been completed at the acquisition date. For public business entities, the amendments in this ASU are effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. The amendments in this ASU should be applied prospectively with earlier application permitted for financial statements that have not been issued. The adoption of this guidance is not expected to have a material impact on WESCO's financial position, results of operations or cash flows. Management does not believe that any other recently issued, but not yet effective, accounting standards if currently adopted would have a material effect on the accompanying financial statements and notes thereto.

ACQUISITIONS

ACQUISITIONS	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS The following table sets forth the consideration paid for acquisitions: Nine Months Ended (In thousands of dollars) September 30, September 30, Fair value of assets acquired $ 89,786 $ 153,430 Fair value of liabilities assumed 21,284 14,625 Cash paid for acquisitions, net of cash acquired $ 68,502 $ 138,805 The fair values of assets acquired and liabilities assumed during the nine months ended September 30, 2015 , which are primarily for the acquisition of Hill Country Electric Supply, LP ("Hill Country"), are based upon preliminary calculations and valuations. WESCO's estimates and assumptions for its preliminary purchase price allocation are subject to change as it obtains additional information for its estimates during the respective measurement periods (up to one year from the respective acquisition date). 2015 Acquisition of Hill Country Electric Supply, LP On May 1, 2015 , WESCO Distribution, Inc. completed the acquisition of Hill Country, an electrical distributor focused on the commercial construction market from nine locations in Central and South Texas with approximately $140 million in annual sales. WESCO funded the purchase price paid at closing with borrowings under its prior 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 $21.1 million and goodwill of $15.8 million . The intangible assets include customer relationships of $13.1 million amortized over 11 years, non-compete agreements of $0.2 million amortized over 5 years, and trademarks of $7.8 million amortized over 12 years. No residual value is estimated for the intangible assets being amortized. Management believes that the majority of goodwill is deductible for tax purposes. 2014 Acquisitions of LaPrairie, Inc., Hazmasters, Inc. and Hi-Line Utility Supply. On February 1, 2014 , WESCO Distribution, Inc., through its wholly-owned Canadian subsidiary, completed the acquisition of LaPrairie, Inc. ("LaPrairie"), a wholesale distributor of electrical products with approximately $30 million in annual sales servicing the transmission, distribution, and substation needs of utilities and utility contractors 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 fair value of intangibles was estimated by management and the allocation resulted in intangible assets of $11.0 million and goodwill of $8.9 million . The majority of goodwill is 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 with approximately $80 million in annual sales servicing customers in the industrial, construction, commercial, institution, and government markets from 14 branches across Canada. WESCO funded the purchase price paid at closing with cash and borrowings under its prior 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 fair value of intangibles was estimated by management and the allocation resulted in intangible assets of $28.1 million and goodwill of $29.5 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. The purchase price was allocated to the respective assets and liabilities based upon their estimated fair values as of the acquisition date. The fair value of intangibles was estimated by management and the allocation resulted in intangible assets of $14.2 million and goodwill of $24.0 million . The majority of goodwill is deductible for tax purposes. For all acquisitions made in the first nine months of 2014, the intangible assets include customer relationships of $38.9 million amortized over 2 to 12 years, supplier relationships of $3.2 million amortized over 10 years, trademarks of $10.9 million , and other intangibles of $0.3 million . Certain trademarks have been assigned an indefinite life while others are amortized over 5 and 10 years. No residual value is estimated for the intangible assets being amortized.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Sep. 30, 2015
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-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-settled stock appreciation rights and performance-based awards with market conditions is determined using the Black-Scholes and Monte Carlo simulation models, respectively. The fair value of restricted stock units and performance-based awards with performance conditions 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, 2015 and 2014 , WESCO granted the following stock-settled appreciation rights, restricted stock units and performance-based awards at the following weighted-average fair values: Three Months Ended Nine Months Ended September 30, September 30, September 30, September 30, Stock-settled appreciation rights granted — — 394,182 274,508 Weighted-average fair value $ — $ — $ 21.68 $ 30.64 Restricted stock units granted 2,730 611 81,022 63,117 Weighted-average fair value $ 54.94 $ 81.88 $ 69.05 $ 85.32 Performance-based awards granted — — 59,661 44,046 Weighted-average fair value $ — $ — $ 67.81 $ 86.65 The fair value of stock-settled appreciation rights was estimated using the following weighted-average assumptions: Three Months Ended Nine Months Ended September 30, September 30, September 30, September 30, Risk free interest rate — — 1.6 % 1.5 % Expected life (in years) 0 0 5 5 Expected volatility — — 32 % 39 % The risk-free interest rate is based on the U.S. Treasury Daily Yield Curve rates as of the grant date. The expected life is based on historical exercise experience and the expected volatility is based on the volatility of the Company's daily stock prices over a five-year period preceding the grant date. The following table sets forth a summary of stock-settled stock appreciation rights and related information for the nine months ended September 30, 2015 : Awards Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at December 31, 2014 2,480,745 $ 50.91 Granted 394,182 69.54 Exercised (229,732 ) 35.87 Forfeited (32,430 ) 75.61 Outstanding at September 30, 2015 2,612,765 54.73 5.4 $ 14,640 Exercisable at September 30, 2015 1,994,736 $ 48.73 4.3 $ 14,640 The following table sets forth a summary of time-based restricted stock units and related information for the nine months ended September 30, 2015 : Awards Weighted- Average Fair Value Unvested at December 31, 2014 185,457 $ 73.87 Granted 81,022 69.05 Vested (67,437 ) 65.39 Forfeited (8,593 ) 75.89 Unvested at September 30, 2015 190,449 $ 74.73 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, 2015 : Awards Weighted- Average Fair Value Unvested at December 31, 2014 130,004 $ 80.21 Granted 59,661 67.81 Vested (38,869 ) 72.25 Forfeited (14,064 ) 82.91 Unvested at September 30, 2015 136,732 $ 76.79 The fair value of the performance shares granted during the nine months ended September 30, 2015 was estimated using the following weighted-average assumptions: Weighted-Average Assumptions Grant date share price $ 69.54 WESCO expected volatility 26.9 % Peer group median volatility 23.2 % Risk-free interest rate 1.05 % Correlation of peer company returns 95.8 % The unvested performance-based awards in the table above include 68,366 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 accounted for as awards with market conditions; compensation cost is recognized over the service period, regardless of whether the market conditions are achieved and the awards ultimately vest. Vesting of the remaining 68,366 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 accounted for as awards with performance conditions; 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 $1.9 million and $2.5 million of non-cash stock-based compensation expense, which is included in selling, general and administrative expenses, for the three months ended September 30, 2015 and 2014 , respectively. WESCO recognized $9.7 million and $11.0 million of non-cash stock-based compensation expense, which is included in selling, general and administrative expenses, for the nine months ended September 30, 2015 and 2014 , respectively. As of September 30, 2015 , there was $23.1 million of total unrecognized compensation cost related to non-vested stock-based compensation arrangements for all awards previously made, of which approximately $5.3 million is expected to be recognized over the remainder of 2015 , $11.2 million in 2016 , $5.9 million in 2017 and $0.7 million in 2018 . During the nine months ended September 30, 2015 and 2014 , the total intrinsic value of all awards exercised and vested was $15.4 million and $24.2 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 . The gross deferred tax benefit associated with the exercise of awards for the nine months ended September 30, 2015 and 2014 totaled $5.6 million and $9.1 million , respectively, and was recorded as an increase to additional capital.

EARNINGS PER SHARE

EARNINGS PER SHARE	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE Basic earnings per share are computed by dividing net income by the weighted-average number of 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 dilutive equity awards and contingently convertible debt. The following tables set forth the details of basic and diluted earnings per share: Three Months Ended September 30, (In thousands, except per share data) 2015 2014 Net income attributable to WESCO International, Inc. $ 63,503 $ 80,816 Weighted-average common shares outstanding used in computing basic earnings per share 43,191 44,475 Common shares issuable upon exercise of dilutive equity awards 538 990 Common shares issuable from contingently convertible debentures (see below for basis of calculation) 5,989 7,778 Weighted-average common shares outstanding and common share equivalents used in computing diluted earnings per share 49,718 53,243 Earnings per share attributable to WESCO International, Inc. Basic $ 1.47 $ 1.82 Diluted $ 1.28 $ 1.52 Nine Months Ended September 30, (In thousands, except per share data) 2015 2014 Net income attributable to WESCO International, Inc. $ 162,273 $ 201,523 Weighted-average common shares outstanding used in computing basic earnings per share 43,860 44,425 Common shares issuable upon exercise of dilutive equity awards 717 1,036 Common shares issuable from contingently convertible debentures (see below for basis of calculation) 6,738 7,901 Weighted-average common shares outstanding and common share equivalents used in computing diluted earnings per share 51,315 53,362 Earnings per share attributable to WESCO International, Inc. Basic $ 3.70 $ 4.54 Diluted $ 3.16 $ 3.78 For the three and nine months ended September 30, 2015 , the computation of diluted earnings per share attributable to WESCO International, Inc. excluded approximately 1.6 million and 1.0 million stock-settled stock appreciation rights at weighted-average exercise prices of $69.29 per share and $74.05 per share, respectively. 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. 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 11,947,602 shares for the 2029 Debentures. For the three and nine months September 30, 2015 , the effect of the 2029 Debentures on diluted earnings per share attributable to WESCO International, Inc. was a decrease of $0.17 and $0.48 , respectively. For the three and nine months 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. In December 2014, the Company's Board of Directors authorized the repurchase of up to $300 million of the Company's common stock through December 31, 2017. During the three months ended September 30, 2015 , the Company entered into an accelerated stock repurchase agreement (the "ASR Transaction") with a financial institution to purchase shares of its common stock. In exchange for an up-front cash payment of $75.0 million , the Company received 1,417,649 shares. The total number of shares ultimately delivered under the ASR Transaction was determined by the average of the volume-weighted average prices of the Company's common stock for each exchange business day during the settlement valuation period. WESCO funded the repurchase with borrowings under its prior revolving credit facility. For the nine months ended September 30, 2015 , WESCO has repurchased 2,468,576 shares of the Company's common stock for $150.0 million . For purposes of computing earnings per share, share repurchases have been reflected as a reduction to common shares outstanding on the respective share delivery dates.

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS	9 Months Ended
	Sep. 30, 2015
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 3% to 5% of the participant’s eligible compensation based on years of continuous service. In addition, for U.S. participants, employer contributions may be made at the discretion of the Board of Directors. For the nine months ended September 30, 2015 and 2014 , WESCO incurred charges of $17.5 million and $23.3 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. 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: Three Months Ended Nine Months Ended September 30, September 30, (In thousands of dollars) 2015 2014 2015 2014 Service cost $ 1,113 $ 912 $ 3,442 $ 2,712 Interest cost 991 1,172 3,064 3,486 Expected return on plan assets (1,299 ) (1,380 ) (4,017 ) (4,103 ) Recognized actuarial gain (4 ) (14 ) (12 ) (43 ) Net periodic benefit cost $ 801 $ 690 $ 2,477 $ 2,052 During the three and nine months ended September 30, 2015 , the Company made aggregate cash contributions of $0.5 million and $1.5 million , respectively, to its defined benefit plans. During the three and nine months ended September 30, 2014 , the Company made aggregate cash contributions of $0.5 million and $1.7 million , respectively, to its defined benefit plans.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES As initially reported in its 2008 Annual Report on Form 10-K, WESCO was a defendant in a lawsuit filed in a state court in Indiana in which a customer, ArcelorMittal Indiana Harbor, Inc. (“AIH”), alleged 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 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. The Company disputed this outcome and filed a post-trial motion challenging the verdict, alleging various errors that occurred during trial. 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 appealed the judgment. On November 10, 2014, the Indiana Court of Appeals reversed the prejudgment interest award, but otherwise affirmed the underlying judgment. A petition for further review of the case was filed with the Indiana Supreme Court. On April 15, 2015, the Company, AIH and the parties’ respective insurance carriers agreed to settle the case. As part of the settlement, the Company's insurers paid $35.8 million to AIH on April 30, 2015 in full and final satisfaction of the judgment, including any prejudgment and post-judgment interest, and AIH agreed to release all claims against the Company and its insurers. The parties also agreed to a dismissal of the pending appeal to the Indiana Supreme Court. To account for the settlement, the Company reversed the previously recorded liability and corresponding receivable of $36.1 million , plus $10.2 million of interest that had accrued in connection with this matter. Accordingly, the settlement of this matter had no net effect on the Company's financial condition or results of operations. 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. WESCO Distribution, Inc. is currently undergoing a compliance audit in the State of Delaware concerning the identification, reporting and escheatment of unclaimed or abandoned property. A third party auditor is conducting the audit on behalf of the State, and the Company has been working with an outside consultant during the audit process and in discussions with the auditors. The Company is defending the audit, the outcome of which cannot be predicted with certainty at this time. After the third party auditor completes its field work, it is expected to issue preliminary findings for review by the Company and the State, and thereafter the auditor is expected to issue a final report of examination. If the Company and State do not reach resolution after further discussion, the State issues a demand for payment, which the Company may either agree to pay or appeal, in full or in part. The Company has recorded a liability for unclaimed property 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.

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2015
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The effective tax rate for the three and nine months ended September 30, 2015 was 27.4% and 28.6% , respectively. The effective tax rate for the three and nine months ended September 30, 2014 was 28.1% . WESCO’s effective tax rate is lower than the federal statutory rate of 35% in both periods 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. There have been no material adjustments to liabilities relating to uncertain tax positions since the last annual disclosure for the year ended December 31, 2014 .

OTHER FINANCIAL INFORMATION

OTHER FINANCIAL INFORMATION	9 Months Ended
	Sep. 30, 2015
Condensed Financial Information [Abstract]
OTHER FINANCIAL INFORMATION	WESCO International, Inc. has outstanding $344.9 million in aggregate principal amount of 2029 Debentures. The 2029 Debentures are fully and unconditionally guaranteed by WESCO Distribution, Inc., a 100% owned subsidiary of WESCO International, Inc., on a senior subordinated basis to all existing and future senior indebtedness of WESCO Distribution, Inc. WESCO Distribution, Inc. 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, Inc. and are fully and unconditionally guaranteed on a senior unsecured basis by WESCO International, Inc. Condensed consolidating financial information for WESCO International, Inc., WESCO Distribution, Inc. and the non-guarantor subsidiaries is presented in the following tables. Condensed Consolidating Balance Sheet September 30, 2015 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Cash and cash equivalents $ — $ 39,779 $ 93,073 $ — $ 132,852 Trade accounts receivable, net — — 1,149,743 — 1,149,743 Inventories, net — 401,669 443,286 — 844,955 Prepaid expenses and other current assets 18 121,802 123,134 (6,414 ) 238,540 Total current assets 18 563,250 1,809,236 (6,414 ) 2,366,090 Intercompany receivables, net — — 1,947,258 (1,947,258 ) — Property, buildings and equipment, net — 57,722 114,067 — 171,789 Intangible assets, net — 4,237 384,751 — 388,988 Goodwill — 255,251 1,410,967 — 1,666,218 Investments in affiliates 3,294,404 3,776,151 — (7,070,555 ) — Other assets 3,875 12,262 33,287 — 49,424 Total assets $ 3,298,297 $ 4,668,873 $ 5,699,566 $ (9,024,227 ) $ 4,642,509 Accounts payable $ — $ 454,216 $ 333,421 $ — $ 787,637 Short-term debt — — 44,419 — 44,419 Other current liabilities 7,291 54,027 129,817 (6,414 ) 184,721 Total current liabilities 7,291 508,243 507,657 (6,414 ) 1,016,777 Intercompany payables, net 1,325,788 621,470 — (1,947,258 ) — Long-term debt, net 180,534 730,813 543,358 — 1,454,705 Other noncurrent liabilities 21,889 256,204 133,086 — 411,179 Total WESCO International, Inc. stockholders' equity 1,762,795 2,552,143 4,518,412 (7,070,555 ) 1,762,795 Noncontrolling interests — — (2,947 ) — (2,947 ) Total liabilities and stockholders’ equity $ 3,298,297 $ 4,668,873 $ 5,699,566 $ (9,024,227 ) $ 4,642,509 Condensed Consolidating Balance Sheet December 31, 2014 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Cash and cash equivalents $ — $ 32,508 $ 95,811 $ — $ 128,319 Trade accounts receivable, net — — 1,117,420 — 1,117,420 Inventories, net — 373,938 445,564 — 819,502 Prepaid expenses and other current assets 12 144,282 147,268 (6,465 ) 285,097 Total current assets 12 550,728 1,806,063 (6,465 ) 2,350,338 Intercompany receivables, net — — 1,806,215 (1,806,215 ) — Property, buildings and equipment, net — 56,735 125,990 — 182,725 Intangible assets, net — 4,733 425,107 — 429,840 Goodwill — 246,771 1,488,669 — 1,735,440 Investments in affiliates 3,304,914 3,828,727 — (7,133,641 ) — Other assets 4,083 12,844 39,167 — 56,094 Total assets $ 3,309,009 $ 4,700,538 $ 5,691,211 $ (8,946,321 ) $ 4,754,437 Accounts payable $ — $ 445,680 $ 319,455 $ — $ 765,135 Short-term debt — — 46,787 — 46,787 Other current liabilities 12,465 113,746 132,204 (6,465 ) 251,950 Total current liabilities 12,465 559,426 498,446 (6,465 ) 1,063,872 Intercompany payables, net 1,168,366 637,849 — (1,806,215 ) — Long-term debt, net 177,638 683,407 505,385 — 1,366,430 Other noncurrent liabilities 21,888 232,544 141,538 — 395,970 Total WESCO International, Inc. stockholders' equity 1,928,652 2,587,312 4,546,329 (7,133,641 ) 1,928,652 Noncontrolling interests — — (487 ) — (487 ) Total liabilities and stockholders’ equity $ 3,309,009 $ 4,700,538 $ 5,691,211 $ (8,946,321 ) $ 4,754,437 Condensed Consolidating Statement of Income and Comprehensive Loss Three Months Ended September 30, 2015 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net sales $ — $ 876,098 $ 1,077,255 $ (29,454 ) $ 1,923,899 Cost of goods sold (excluding depreciation and amortization) — 705,698 866,869 (29,454 ) 1,543,113 Selling, general and administrative expenses 5 131,648 126,498 — 258,151 Depreciation and amortization — 4,866 11,421 — 16,287 Results of affiliates’ operations 66,944 48,419 — (115,363 ) — Interest expense (income), net 6,253 19,681 (5,517 ) — 20,417 Provision for income taxes (1,698 ) 3,988 21,257 — 23,547 Net income 62,384 58,636 56,727 (115,363 ) 62,384 Net loss attributable to noncontrolling interests — — (1,119 ) — (1,119 ) Net income attributable to WESCO International, Inc. $ 62,384 $ 58,636 $ 57,846 $ (115,363 ) $ 63,503 Other comprehensive loss: Foreign currency translation adjustments (95,377 ) (95,377 ) (95,377 ) 190,754 (95,377 ) Comprehensive loss income attributable to WESCO International, Inc. $ (32,993 ) $ (36,741 ) $ (37,531 ) $ 75,391 $ (31,874 ) Condensed Consolidating Statement of Income and Comprehensive Income Three Months Ended September 30, 2014 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net sales $ — $ 932,948 $ 1,174,935 $ (29,733 ) $ 2,078,150 Cost of goods sold (excluding depreciation and amortization) — 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 (income), 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 Net income attributable to noncontrolling interests — — 2 — 2 Net income attributable to WESCO International, Inc. $ 80,818 $ 77,248 $ 70,580 $ (147,830 ) $ 80,816 Other comprehensive loss: Foreign currency translation adjustments (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 Condensed Consolidating Statement of Income and Comprehensive Loss Nine Months Ended September 30, 2015 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net sales $ — $ 2,600,150 $ 3,144,759 $ (87,962 ) $ 5,656,947 Cost of goods sold (excluding depreciation and amortization) — 2,089,594 2,525,204 (87,962 ) 4,526,836 Selling, general and administrative expenses 22 415,971 381,987 — 797,980 Depreciation and amortization — 14,640 33,707 — 48,347 Results of affiliates’ operations 173,137 131,074 — (304,211 ) — Interest expense (income), net 18,641 55,561 (14,278 ) — 59,924 Provision for income taxes (5,339 ) 6,976 62,410 — 64,047 Net income 159,813 148,482 155,729 (304,211 ) 159,813 Net loss attributable to noncontrolling interests — — (2,460 ) — (2,460 ) Net income attributable to WESCO International, Inc. $ 159,813 $ 148,482 $ 158,189 $ (304,211 ) $ 162,273 Other comprehensive loss: Foreign currency translation adjustments (183,634 ) (183,634 ) (183,634 ) 367,268 (183,634 ) Comprehensive loss attributable to WESCO International, Inc. $ (23,821 ) $ (35,152 ) $ (25,445 ) $ 63,057 $ (21,361 ) Condensed Consolidating Statement of Income and Comprehensive Income Nine Months Ended September 30, 2014 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net sales $ — $ 2,656,619 $ 3,323,237 $ (85,715 ) $ 5,894,141 Cost of goods sold (excluding depreciation and amortization) — 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 (income), 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 Net loss attributable to noncontrolling interests — — (64 ) — (64 ) Net income attributable to WESCO International, Inc. $ 201,459 $ 190,949 $ 188,542 $ (379,427 ) $ 201,523 Other comprehensive loss: Foreign currency translation adjustments (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 Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2015 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net cash (used in) provided by operating activities $ (3,332 ) $ 210,270 $ (30,974 ) $ — $ 175,964 Investing activities: Capital expenditures — (12,137 ) (4,105 ) — (16,242 ) Acquisition payments, net of cash acquired — (68,502 ) — — (68,502 ) Other — (157,422 ) 1,791 157,422 1,791 Net cash used in investing activities — (238,061 ) (2,314 ) 157,422 (82,953 ) Financing activities: Borrowings 157,422 936,352 359,546 (157,422 ) 1,295,898 Repayments — (888,352 ) (313,806 ) — (1,202,158 ) Equity activities (154,090 ) — — — (154,090 ) Other — (12,938 ) — — (12,938 ) Net cash provided by (used in) financing activities 3,332 35,062 45,740 (157,422 ) (73,288 ) Effect of exchange rate changes on cash and cash equivalents — — (15,190 ) — (15,190 ) Net change in cash and cash equivalents — 7,271 (2,738 ) — 4,533 Cash and cash equivalents at the beginning of period — 32,508 95,811 — 128,319 Cash and cash equivalents at the end of period $ — $ 39,779 $ 93,073 $ — $ 132,852 Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2014 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net cash (used in) provided by operating activities $ (5,202 ) $ 68,291 $ 76,731 $ — $ 139,820 Investing activities: Capital expenditures — (10,811 ) (5,225 ) — (16,036 ) Acquisition payments, net of cash acquired — (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 ) Equity activities (640 ) — — — (640 ) Other — (8,562 ) (110 ) — (8,672 ) Net cash provided by (used in) 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 period — 31,695 92,030 — 123,725 Cash and cash equivalents at the end of period $ — $ 37,639 $ 72,729 $ — $ 110,368 The unaudited Condensed Consolidating Statement of Cash Flows for the nine months ended September 30, 2014 includes certain reclassifications to previously reported amounts to conform to the current period presentation.

Subsequent Events SUBSEQUENT EV

Subsequent Events SUBSEQUENT EVENTS (Notes)	9 Months Ended
	Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent Events [Text Block]	SUBSEQUENT EVENTS On October 30, 2015 , WESCO International, Inc., through its wholly-owned subsidiary WESCO Distribution, Inc., acquired a U.S. electrical distributor focused on commercial construction and lighting with annual sales of approximately $115 million . A preliminary purchase price allocation will be completed during the fourth quarter of 2015.

Debt (Notes)

Debt (Notes)	9 Months Ended
	Sep. 30, 2015
Debt Instrument [Line Items]
Debt Disclosure [Text Block]	6. DEBT Revolving Credit Facility On September 24, 2015, WESCO International, Inc., WESCO Distribution, Inc. and certain other subsidiaries of the Company entered into a $600 million revolving credit facility (the “Revolving Credit Facility”), which contains a letter of credit sub-facility of up to $125 million, pursuant to the terms and conditions of a Second Amended and Restated Credit Agreement (the "Credit Agreement"). The Revolving Credit Facility contains an accordion feature allowing WESCO Distribution, Inc. to request increases to the borrowing commitments, subject to customary conditions. This accordion feature increased from $100 million to $200 million in the aggregate. The Revolving Credit Facility replaces WESCO Distribution Inc.’s prior revolving credit facility entered into on December 12, 2012. The Revolving Credit Facility matures in September 2020 and consists of two separate sub-facilities: (i) a Canadian sub-facility with a borrowing limit of up to $400 million, which is collateralized by substantially all assets of WESCO Canada and the other Canadian Borrowers, other than, among other things, real property, in each case, subject to customary exceptions and limitations, and (ii) a U.S sub-facility with a borrowing limit of up to $600 million less the amount of outstanding borrowings under the Canadian sub-facility. The U.S. sub-facility is collateralized by substantially all assets of WESCO Distribution, Inc. and its subsidiaries which are party to the Credit Agreement, other than, among other things, real property and accounts receivable sold or intended to be sold pursuant to WESCO Distribution Inc.’s accounts receivable securitization facility. The applicable interest rate for borrowings under the Revolving Credit Facility includes interest rate spreads based on available borrowing capacity that range between 1.25% and 1.75% for LIBOR-based borrowings and 0.25% and 0.75% for prime rate-based borrowings. The Credit Agreement requires compliance with conditions precedent that must be satisfied prior to any borrowing as well as ongoing compliance with certain customary covenants. The Credit Agreement contains customary events of default. Accounts Receivable Securitization Facility On September 24, 2015, WESCO Distribution, Inc. amended and restated its accounts receivable securitization facility (the "Receivables Facility") pursuant to the terms and conditions of a Fourth Amended and Restated Receivables Purchase Agreement (the “Receivables Purchase Agreement”), by and among WESCO Receivables Corp. (“WESCO Receivables”), WESCO Distribution, Inc., the various purchaser groups from time to time party thereto and PNC Bank, National Association, as Administrator. The Receivables Purchase Agreement amends and restates the receivables purchase agreement entered into on April 13, 2009. The Receivables Purchase Agreement increases the purchase limit from $500 million to $550 million, with the opportunity to exercise an accordion feature which permits increases in the purchase limit of up to $100 million, extends the term of the Receivables Facility to September 24, 2018 and adds and amends certain defined terms. The interest rate spread and commitment fee of the Receivables Facility remains 0.95% and 0.45%, respectively. Under the Receivables Facility, WESCO sells, on a continuous basis, an undivided interest in all domestic accounts receivable to WESCO Receivables, a wholly owned special purpose entity (the “SPE”). The SPE sells, without recourse, a senior undivided interest in the receivables to financial institutions for cash while maintaining a subordinated undivided interest in the receivables, in the form of overcollateralization. WESCO has agreed to continue servicing the sold receivables for the third-party conduits and financial institutions at market rates; accordingly, no servicing asset or liability has been recorded.

ACCOUNTING POLICIES (Policies)

ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying 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 information should be read in conjunction with the audited Consolidated Financial Statements and Notes thereto included in WESCO’s 2014 Annual Report on Form 10-K as filed with the SEC on February 24, 2015. The Condensed Consolidated Balance Sheet at December 31, 2014 was derived from the audited Consolidated Financial Statements as of that date, but does not include all of the disclosures required by accounting principles generally accepted in the United States of America. The unaudited Condensed Consolidated Balance Sheet as of September 30, 2015 , the unaudited Condensed Consolidated Statements of Income and Comprehensive Income (Loss) for the three and nine months ended September 30, 2015 and 2014 , respectively, and the unaudited Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2015 and 2014 , 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 presented herein. All adjustments reflected in the unaudited condensed consolidated financial information are of a normal recurring nature unless indicated. The results for the interim periods presented herein are not necessarily indicative of the results to be expected for the full year.
Reclassification	The Condensed Consolidated Balance Sheet at December 31, 2014 and the unaudited Condensed Consolidated Statement of Cash Flows for the nine months ended September 30, 2014 include certain reclassifications to previously reported amounts to conform to the current period presentation.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company measures the fair value of financial assets and liabilities in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (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 that prioritizes the inputs to valuation techniques used to measure fair value and requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to measurements involving significant unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are as follows: • Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that are accessible at the measurement date. • 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, 2015 , the carrying value of WESCO’s 6.0% Convertible Senior Debentures due 2029 (the "2029 Debentures") was $180.5 million and the fair value was approximately $578.4 million . At December 31, 2014 , the carrying value of WESCO’s 2029 Debentures was $177.6 million and the fair value was approximately $936.1 million . The reported carrying amounts of WESCO’s other debt instruments approximate their fair values. The Company uses a market approach to fair value all of its debt instruments, utilizing quoted prices in active markets, interest rates and other relevant information generated by market transactions involving similar instruments. Therefore, all of the Company's debt instruments are classified as Level 2 within the valuation hierarchy. For all of the Company's remaining financial instruments, consisting of cash and cash equivalents, accounts receivable, accounts payable and other accrued liabilities, carrying values are considered to approximate fair value due to the short maturity of these instruments.
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In June 2014, the FASB issued Accounting Standards Update ("ASU") 2014-12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period . The amendments in this ASU require a reporting entity to treat a performance target that affects vesting and could be achieved after the requisite service period as a performance condition. A reporting entity should apply FASB ASC Topic 718, Compensation — Stock Compensation , to awards with performance conditions that affect vesting. For all entities, ASU 2014-12 is effective for annual periods and interim periods within those annual periods, beginning after December 15, 2015. Early adoption is permitted. This ASU may be adopted either prospectively for share-based payment awards granted or modified on or after the effective date, or retrospectively, using a modified retrospective approach. The modified retrospective approach would apply to share-based payment awards outstanding as of the beginning of the earliest annual period presented in the financial statements on adoption and to all new or modified awards thereafter. The adoption of this guidance is not expected to have a material impact on WESCO's financial position, results of operations or cash flows. In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers: Deferral of Effective Date . The Company previously reported that in May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which 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 ASU 2014-09 is for companies to recognize revenue for 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. ASU 2014-09 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. The amendments in ASU 2015-14 defer the effective date of the new revenue recognition guidance to annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Early adoption is permitted to the original effective date of December 15, 2016, including interim periods within that reporting period. Management is currently evaluating the future impact of this guidance on WESCO's consolidated financial statements and notes thereto. In August 2015, the FASB issued ASU 2015-15, Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements . The Company previously reported that in April 2015, the FASB issued ASU 2015-03, Simplifying the Presentation of Debt Issuance Costs , which simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The amendments in ASU 2015-15 address the absence of authoritative guidance within ASU 2015-03 for debt issuance costs related to line-of-credit arrangements such that the SEC staff would not object to an entity deferring and presenting debt issuance costs as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. ASU 2015-15 and ASU 2015-03 are effective for financial statements of public business entities issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption is permitted for financial statements that have not been previously issued. The adoption of this guidance is not expected to have a material impact on WESCO's financial position, results of operations or cash flows. In September 2015, the FASB issued ASU 2015-16, Business Combinations: Simplifying the Accounting for Measurement-Period Adjustments . The amendments in this ASU require that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined; calculated as if the accounting had been completed at the acquisition date. For public business entities, the amendments in this ASU are effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. The amendments in this ASU should be applied prospectively with earlier application permitted for financial statements that have not been issued. The adoption of this guidance is not expected to have a material impact on WESCO's financial position, results of operations or cash flows. Management does not believe that any other recently issued, but not yet effective, accounting standards if currently adopted would have a material effect on the accompanying financial statements and notes thereto.

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	Nine Months Ended (In thousands of dollars) September 30, September 30, Fair value of assets acquired $ 89,786 $ 153,430 Fair value of liabilities assumed 21,284 14,625 Cash paid for acquisitions, net of cash acquired $ 68,502 $ 138,805

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	During the three and nine months ended September 30, 2015 and 2014 , WESCO granted the following stock-settled appreciation rights, restricted stock units and performance-based awards at the following weighted-average fair values: Three Months Ended Nine Months Ended September 30, September 30, September 30, September 30, Stock-settled appreciation rights granted — — 394,182 274,508 Weighted-average fair value $ — $ — $ 21.68 $ 30.64 Restricted stock units granted 2,730 611 81,022 63,117 Weighted-average fair value $ 54.94 $ 81.88 $ 69.05 $ 85.32 Performance-based awards granted — — 59,661 44,046 Weighted-average fair value $ — $ — $ 67.81 $ 86.65
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-settled stock appreciation rights and related information for the nine months ended September 30, 2015 : Awards Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at December 31, 2014 2,480,745 $ 50.91 Granted 394,182 69.54 Exercised (229,732 ) 35.87 Forfeited (32,430 ) 75.61 Outstanding at September 30, 2015 2,612,765 54.73 5.4 $ 14,640 Exercisable at September 30, 2015 1,994,736 $ 48.73 4.3 $ 14,640
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]	The following table sets forth a summary of time-based restricted stock units and related information for the nine months ended September 30, 2015 : Awards Weighted- Average Fair Value Unvested at December 31, 2014 185,457 $ 73.87 Granted 81,022 69.05 Vested (67,437 ) 65.39 Forfeited (8,593 ) 75.89 Unvested at September 30, 2015 190,449 $ 74.73
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, 2015 : Awards Weighted- Average Fair Value Unvested at December 31, 2014 130,004 $ 80.21 Granted 59,661 67.81 Vested (38,869 ) 72.25 Forfeited (14,064 ) 82.91 Unvested at September 30, 2015 136,732 $ 76.79
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Weighted-Average Assumptions Grant date share price $ 69.54 WESCO expected volatility 26.9 % Peer group median volatility 23.2 % Risk-free interest rate 1.05 % Correlation of peer company returns 95.8 %
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Three Months Ended Nine Months Ended September 30, September 30, September 30, September 30, Risk free interest rate — — 1.6 % 1.5 % Expected life (in years) 0 0 5 5 Expected volatility — — 32 % 39 %

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following tables set forth the details of basic and diluted earnings per share: Three Months Ended September 30, (In thousands, except per share data) 2015 2014 Net income attributable to WESCO International, Inc. $ 63,503 $ 80,816 Weighted-average common shares outstanding used in computing basic earnings per share 43,191 44,475 Common shares issuable upon exercise of dilutive equity awards 538 990 Common shares issuable from contingently convertible debentures (see below for basis of calculation) 5,989 7,778 Weighted-average common shares outstanding and common share equivalents used in computing diluted earnings per share 49,718 53,243 Earnings per share attributable to WESCO International, Inc. Basic $ 1.47 $ 1.82 Diluted $ 1.28 $ 1.52 Nine Months Ended September 30, (In thousands, except per share data) 2015 2014 Net income attributable to WESCO International, Inc. $ 162,273 $ 201,523 Weighted-average common shares outstanding used in computing basic earnings per share 43,860 44,425 Common shares issuable upon exercise of dilutive equity awards 717 1,036 Common shares issuable from contingently convertible debentures (see below for basis of calculation) 6,738 7,901 Weighted-average common shares outstanding and common share equivalents used in computing diluted earnings per share 51,315 53,362 Earnings per share attributable to WESCO International, Inc. Basic $ 3.70 $ 4.54 Diluted $ 3.16 $ 3.78

EMPLOYEE BENEFIT PLANS Schedule

EMPLOYEE BENEFIT PLANS Schedule of Net Benefit Costs (Tables)	9 Months Ended
	Sep. 30, 2015
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: Three Months Ended Nine Months Ended September 30, September 30, (In thousands of dollars) 2015 2014 2015 2014 Service cost $ 1,113 $ 912 $ 3,442 $ 2,712 Interest cost 991 1,172 3,064 3,486 Expected return on plan assets (1,299 ) (1,380 ) (4,017 ) (4,103 ) Recognized actuarial gain (4 ) (14 ) (12 ) (43 ) Net periodic benefit cost $ 801 $ 690 $ 2,477 $ 2,052

OTHER FINANCIAL INFORMATION (Ta

OTHER FINANCIAL INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2015
Condensed Balance Sheet Statements, Captions [Line Items]
Condensed Balance Sheet [Table Text Block]	Condensed Consolidating Balance Sheet September 30, 2015 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Cash and cash equivalents $ — $ 39,779 $ 93,073 $ — $ 132,852 Trade accounts receivable, net — — 1,149,743 — 1,149,743 Inventories, net — 401,669 443,286 — 844,955 Prepaid expenses and other current assets 18 121,802 123,134 (6,414 ) 238,540 Total current assets 18 563,250 1,809,236 (6,414 ) 2,366,090 Intercompany receivables, net — — 1,947,258 (1,947,258 ) — Property, buildings and equipment, net — 57,722 114,067 — 171,789 Intangible assets, net — 4,237 384,751 — 388,988 Goodwill — 255,251 1,410,967 — 1,666,218 Investments in affiliates 3,294,404 3,776,151 — (7,070,555 ) — Other assets 3,875 12,262 33,287 — 49,424 Total assets $ 3,298,297 $ 4,668,873 $ 5,699,566 $ (9,024,227 ) $ 4,642,509 Accounts payable $ — $ 454,216 $ 333,421 $ — $ 787,637 Short-term debt — — 44,419 — 44,419 Other current liabilities 7,291 54,027 129,817 (6,414 ) 184,721 Total current liabilities 7,291 508,243 507,657 (6,414 ) 1,016,777 Intercompany payables, net 1,325,788 621,470 — (1,947,258 ) — Long-term debt, net 180,534 730,813 543,358 — 1,454,705 Other noncurrent liabilities 21,889 256,204 133,086 — 411,179 Total WESCO International, Inc. stockholders' equity 1,762,795 2,552,143 4,518,412 (7,070,555 ) 1,762,795 Noncontrolling interests — — (2,947 ) — (2,947 ) Total liabilities and stockholders’ equity $ 3,298,297 $ 4,668,873 $ 5,699,566 $ (9,024,227 ) $ 4,642,509 Condensed Consolidating Balance Sheet December 31, 2014 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Cash and cash equivalents $ — $ 32,508 $ 95,811 $ — $ 128,319 Trade accounts receivable, net — — 1,117,420 — 1,117,420 Inventories, net — 373,938 445,564 — 819,502 Prepaid expenses and other current assets 12 144,282 147,268 (6,465 ) 285,097 Total current assets 12 550,728 1,806,063 (6,465 ) 2,350,338 Intercompany receivables, net — — 1,806,215 (1,806,215 ) — Property, buildings and equipment, net — 56,735 125,990 — 182,725 Intangible assets, net — 4,733 425,107 — 429,840 Goodwill — 246,771 1,488,669 — 1,735,440 Investments in affiliates 3,304,914 3,828,727 — (7,133,641 ) — Other assets 4,083 12,844 39,167 — 56,094 Total assets $ 3,309,009 $ 4,700,538 $ 5,691,211 $ (8,946,321 ) $ 4,754,437 Accounts payable $ — $ 445,680 $ 319,455 $ — $ 765,135 Short-term debt — — 46,787 — 46,787 Other current liabilities 12,465 113,746 132,204 (6,465 ) 251,950 Total current liabilities 12,465 559,426 498,446 (6,465 ) 1,063,872 Intercompany payables, net 1,168,366 637,849 — (1,806,215 ) — Long-term debt, net 177,638 683,407 505,385 — 1,366,430 Other noncurrent liabilities 21,888 232,544 141,538 — 395,970 Total WESCO International, Inc. stockholders' equity 1,928,652 2,587,312 4,546,329 (7,133,641 ) 1,928,652 Noncontrolling interests — — (487 ) — (487 ) Total liabilities and stockholders’ equity $ 3,309,009 $ 4,700,538 $ 5,691,211 $ (8,946,321 ) $ 4,754,437

OTHER FINANCIAL INFORMATION Con

OTHER FINANCIAL INFORMATION Condensed Income Statement (Tables)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Condensed Income Statements, Captions [Line Items]
Condensed Income Statement [Table Text Block]	Condensed Consolidating Statement of Income and Comprehensive Loss Three Months Ended September 30, 2015 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net sales $ — $ 876,098 $ 1,077,255 $ (29,454 ) $ 1,923,899 Cost of goods sold (excluding depreciation and amortization) — 705,698 866,869 (29,454 ) 1,543,113 Selling, general and administrative expenses 5 131,648 126,498 — 258,151 Depreciation and amortization — 4,866 11,421 — 16,287 Results of affiliates’ operations 66,944 48,419 — (115,363 ) — Interest expense (income), net 6,253 19,681 (5,517 ) — 20,417 Provision for income taxes (1,698 ) 3,988 21,257 — 23,547 Net income 62,384 58,636 56,727 (115,363 ) 62,384 Net loss attributable to noncontrolling interests — — (1,119 ) — (1,119 ) Net income attributable to WESCO International, Inc. $ 62,384 $ 58,636 $ 57,846 $ (115,363 ) $ 63,503 Other comprehensive loss: Foreign currency translation adjustments (95,377 ) (95,377 ) (95,377 ) 190,754 (95,377 ) Comprehensive loss income attributable to WESCO International, Inc. $ (32,993 ) $ (36,741 ) $ (37,531 ) $ 75,391 $ (31,874 ) Condensed Consolidating Statement of Income and Comprehensive Loss Nine Months Ended September 30, 2015 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net sales $ — $ 2,600,150 $ 3,144,759 $ (87,962 ) $ 5,656,947 Cost of goods sold (excluding depreciation and amortization) — 2,089,594 2,525,204 (87,962 ) 4,526,836 Selling, general and administrative expenses 22 415,971 381,987 — 797,980 Depreciation and amortization — 14,640 33,707 — 48,347 Results of affiliates’ operations 173,137 131,074 — (304,211 ) — Interest expense (income), net 18,641 55,561 (14,278 ) — 59,924 Provision for income taxes (5,339 ) 6,976 62,410 — 64,047 Net income 159,813 148,482 155,729 (304,211 ) 159,813 Net loss attributable to noncontrolling interests — — (2,460 ) — (2,460 ) Net income attributable to WESCO International, Inc. $ 159,813 $ 148,482 $ 158,189 $ (304,211 ) $ 162,273 Other comprehensive loss: Foreign currency translation adjustments (183,634 ) (183,634 ) (183,634 ) 367,268 (183,634 ) Comprehensive loss attributable to WESCO International, Inc. $ (23,821 ) $ (35,152 ) $ (25,445 ) $ 63,057 $ (21,361 ) Condensed Consolidating Statement of Income and Comprehensive Income Three Months Ended September 30, 2014 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net sales $ — $ 932,948 $ 1,174,935 $ (29,733 ) $ 2,078,150 Cost of goods sold (excluding depreciation and amortization) — 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 (income), 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 Net income attributable to noncontrolling interests — — 2 — 2 Net income attributable to WESCO International, Inc. $ 80,818 $ 77,248 $ 70,580 $ (147,830 ) $ 80,816 Other comprehensive loss: Foreign currency translation adjustments (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	Condensed Consolidating Statement of Income and Comprehensive Income Nine Months Ended September 30, 2014 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net sales $ — $ 2,656,619 $ 3,323,237 $ (85,715 ) $ 5,894,141 Cost of goods sold (excluding depreciation and amortization) — 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 (income), 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 Net loss attributable to noncontrolling interests — — (64 ) — (64 ) Net income attributable to WESCO International, Inc. $ 201,459 $ 190,949 $ 188,542 $ (379,427 ) $ 201,523 Other comprehensive loss: Foreign currency translation adjustments (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

OTHER FINANCIAL INFORMATION C24

OTHER FINANCIAL INFORMATION Condensed Cash Flow Statement (Tables)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Condensed Cash Flow Statements, Captions [Line Items]
Condensed Cash Flow Statement [Table Text Block]	Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2015 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net cash (used in) provided by operating activities $ (3,332 ) $ 210,270 $ (30,974 ) $ — $ 175,964 Investing activities: Capital expenditures — (12,137 ) (4,105 ) — (16,242 ) Acquisition payments, net of cash acquired — (68,502 ) — — (68,502 ) Other — (157,422 ) 1,791 157,422 1,791 Net cash used in investing activities — (238,061 ) (2,314 ) 157,422 (82,953 ) Financing activities: Borrowings 157,422 936,352 359,546 (157,422 ) 1,295,898 Repayments — (888,352 ) (313,806 ) — (1,202,158 ) Equity activities (154,090 ) — — — (154,090 ) Other — (12,938 ) — — (12,938 ) Net cash provided by (used in) financing activities 3,332 35,062 45,740 (157,422 ) (73,288 ) Effect of exchange rate changes on cash and cash equivalents — — (15,190 ) — (15,190 ) Net change in cash and cash equivalents — 7,271 (2,738 ) — 4,533 Cash and cash equivalents at the beginning of period — 32,508 95,811 — 128,319 Cash and cash equivalents at the end of period $ — $ 39,779 $ 93,073 $ — $ 132,852	Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2014 (In thousands of dollars) WESCO International, Inc. WESCO Distribution, Inc. Non-Guarantor Subsidiaries Consolidating and Eliminating Entries Consolidated Net cash (used in) provided by operating activities $ (5,202 ) $ 68,291 $ 76,731 $ — $ 139,820 Investing activities: Capital expenditures — (10,811 ) (5,225 ) — (16,036 ) Acquisition payments, net of cash acquired — (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 ) Equity activities (640 ) — — — (640 ) Other — (8,562 ) (110 ) — (8,672 ) Net cash provided by (used in) 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 period — 31,695 92,030 — 123,725 Cash and cash equivalents at the end of period $ — $ 37,639 $ 72,729 $ — $ 110,368

ORGANIZATION (Details)

ORGANIZATION (Details)	Sep. 30, 2015distribution_centers	Sep. 30, 2015customers	Sep. 30, 2015countries	Sep. 30, 2015branches	Sep. 30, 2014branches
Restructuring Cost and Reserve [Line Items]
Active customers (in customers)		75,000
Full service branches (in branches)	9			485
Additional countries (in countries) | countries			16
Hazmasters, Inc. [Member]
Restructuring Cost and Reserve [Line Items]
Full service branches (in branches) | branches					14

ACCOUNTING POLICIES (Details)

ACCOUNTING POLICIES (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Long-term Debt, Fair Value	$ 578.4	$ 936.1
Fixed Rate Debt, Par Value	$ 180.5	$ 177.6

ACQUISITIONS - ACQUISITIONS (De

ACQUISITIONS - ACQUISITIONS (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)distribution_centers	Sep. 30, 2014USD ($)branches	Sep. 30, 2015USD ($)	Sep. 30, 2015branches
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets		$ 153,430	$ 89,786
Payments to Acquire Businesses, Gross	$ 68,502	138,805
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		$ 14,625	$ 21,284
Number of Stores	9			485
Hill Country Electric Supply [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	May 1, 2015
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period	$ 140,000
Finite-lived Intangible Assets Acquired	21,100
Goodwill, Acquired During Period	15,800
Number of Stores		9
LaPrairie [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition		Feb. 1, 2014
Finite-lived Intangible Assets Acquired		$ 11,000
LaPrairie, Inc. [Member]
Business Acquisition [Line Items]
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period		30,000
Goodwill, Acquired During Period		$ 8,900
Hazmasters, Inc. [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition		Mar. 17, 2014
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period		$ 80,000
Finite-lived Intangible Assets Acquired		28,100
Goodwill, Acquired During Period		$ 29,500
Number of Stores | branches		14
Hi-Line [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition		Jun. 11, 2014
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period		$ 30,000
Finite-lived Intangible Assets Acquired		14,200
Goodwill, Acquired During Period		24,000
Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		38,900
Customer Relationships [Member] | Hill Country Electric Supply [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 13,100
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	11 years
Noncompete Agreements [Member] | Hill Country Electric Supply [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 200
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years
Supplier Relationships [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		$ 3,200
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		10 years
Trademarks [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		$ 10,900
Trademarks [Member] | Hill Country Electric Supply [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 7,800
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	12 years
Other Intangible Assets [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired		$ 300
Minimum [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		2 years
Minimum [Member] | Trademarks [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		5 years
Maximum [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		12 years
Maximum [Member] | Trademarks [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		10 years

SCHEDULE OF SHARE-BASED COMPENS

SCHEDULE OF SHARE-BASED COMPENSATION, STOCK OPTIONS AND STOCK APPRECIATION RIGHTS AWARD ACTIVITY (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Share-based Compensation Arrangement By Share-based Payment Award, Options and Stock Appreciation Rights, Outstanding [Roll Forward]
Weighted Average Exercise Price, Exercises in Period (in dollars per share)			$ 35.87
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			$ 69.54
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 14,640,000		$ 14,640,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 54.73		$ 54.73		$ 50.91
Share-based Compensation Arrangement By Share-based Payment Award, Options and Stock Appreciation Rights, Outstanding [Roll Forward]
Beginning of Year (in shares)	1,994,736		1,994,736
Grants in Period (in shares)	0	0	394,182	274,508
Exercises in Period (in shares)			229,732
Forfeitures in Period (in shares)			32,430
Weighted Average Exercise Price, Forfeitures in Period (in dollars per share)			$ 75.61
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 48.73		$ 48.73
Weighted Average Remaining Contractual Term, Outstanding (in years)			5 years 4 months 24 days
Weighted Average Remaining Contractual Term, Exercisable (in years)			4 years 3 months 18 days
Aggregate Intrinsic Value, Outstanding	$ 14,640,000		$ 14,640,000
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	2,612,765		2,612,765		2,480,745

SCHEDULE OF SHARE-BASED PAYMENT

SCHEDULE OF SHARE-BASED PAYMENT AWARD, VALUATION ASSUMPTIONS (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate	0.00%	0.00%	1.60%	1.50%
Expected life (in years)	0 years	0 years	5 years	5 years
WESCO expected volatility	0.00%	0.00%	32.00%	39.00%
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	0	0	394,182	274,508
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	$ 21.68	$ 30.64
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	2,730	611	81,022	63,117
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 54.94	$ 81.88	$ 69.05	$ 85.32
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	0	0	59,661	44,046
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	$ 67.81	$ 86.65
Risk free interest rate			0.00%
WESCO expected volatility			0.00%

SUMMARY OF RESTRICTED STOCK UNI

SUMMARY OF RESTRICTED STOCK UNITS (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested (in shares)	190,449		190,449		185,457
Granted (in shares)	2,730	611	81,022	63,117
Vested (in shares)			(67,437)
Forfeited (in shares)			(8,593)
Unvested, Weighted Average Fair Value (in dollars per share)	$ 74.73		$ 74.73		$ 73.87
Granted, Weighted Average Fair Value (in dollars per share)	$ 54.94	$ 81.88	69.05	$ 85.32
Vested in Period, Weighted Average Fair Value (in dollars per share)			65.39
Forfeited in Period, Weighted Average Fair Value (in dollars per share)			$ 75.89

SUMMARY OF PERFORMANCE-BASED AW

SUMMARY OF PERFORMANCE-BASED AWARDS (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested (in shares)	136,732		136,732		130,004
Granted (in shares)	0	0	59,661	44,046
Vested (in shares)			(38,869)
Forfeited (in shares)			(14,064)
Unvested, Weighted Average Fair Value (in dollars per share)	$ 76.79		$ 76.79		$ 80.21
Granted, Weighted Average Fair Value (in dollars per share)	$ 0	$ 0	67.81	$ 86.65
Vested in Period, Weighted Average Fair Value (in dollars per share)			72.25
Forfeited in Period, Weighted Average Fair Value (in dollars per share)			$ 82.91
Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested (in shares)	68,366		68,366

SCHEDULE OF SHARE-BASED PAYME32

SCHEDULE OF SHARE-BASED PAYMENT AWARD, PERFORMANCE-BASED AWARDS, VALUATION ASSUMPTIONS (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Feb. 17, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
WESCO expected volatility	0.00%	0.00%	32.00%	39.00%
Risk free interest rate	0.00%	0.00%	1.60%	1.50%
Correlation			0.00%
Fair Value Assumptions, Expected Volatility Rate			0.00%
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price					$ 69.54
WESCO expected volatility			0.00%
Risk free interest rate			0.00%

STOCK-BASED COMPENSATION (Detai

STOCK-BASED COMPENSATION (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 1.9	$ 2.5	$ 9.7	$ 11
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested				15.4	24.2
Total unrecognized compensation cost		$ 23.1		23.1
Cash received from exercise of options					0.8
Tax benefit associated with exercise of awards				$ 5.6	$ 9.1
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)		68,366		68,366
Scenario, Forecast [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 5.3					$ 0.7	$ 5.9	$ 11.2

SCHEDULE OF EARNINGS PER SHARE,

SCHEDULE OF EARNINGS PER SHARE, BASIC AND DILUTED (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Net income (loss) attributable to WESCO International, Inc.	$ 63,503	$ 80,816	$ 162,273	$ 201,523
Weighted average common shares outstanding used in computing basic earnings per share (in shares)	43,191	44,475	43,860	44,425
Common shares issuable upon exercise of dilutive stock options (in shares)	538	990	717	1,036
Common shares issuable from contingently convertible debentures (in shares)	5,989	7,778	6,738	7,901
Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share (in shares)	49,718	53,243	51,315	53,362
Earnings Per Share, Basic and Diluted [Abstract]
Basic (in dollars per share)	$ 1.47	$ 1.82	$ 3.70	$ 4.54
Diluted (in dollars per share)	$ 1.28	$ 1.52	$ 3.16	$ 3.78

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Earnings Per Share Dilution Limit (in shares)	5,989,000	7,778,000	6,738,000	7,901,000
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	1,600,000	300,000	1,000,000	500,000
Antidilutive Securities Excluded from Computation of Net Income, Per Outstanding Unit, Amount	$ 69.29	$ 84.47	$ 74.05	$ 79.29
Convertible Debt Securities [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)	11,947,602
Dilutive Securities, Effect on Basic Earnings Per Share	$ 0.17	$ 0.26	$ 0.48	$ 0.65

EARNINGS PER SHARE Accelerated

EARNINGS PER SHARE Accelerated Share Repurchase (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Accelerated Share Repurchases [Line Items]
Payments for Repurchase of Common Stock		$ (155,775)	$ (6,931)
Stock Repurchase Program, Authorized Amount	$ 300,000	300,000
Repurchase Agreements [Member]
Accelerated Share Repurchases [Line Items]
Payments for Repurchase of Common Stock	$ (75,000)	$ (150,000)
Treasury Stock, Shares, Acquired	1,417,649	2,468,576

EMPLOYEE BENEFIT PLANS (Details

EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Compensation and Retirement Disclosure [Abstract]
Defined Benefit Plan, Contributions by Employer	$ 0.5	$ 0.5	$ 1.5	$ 1.7
Schedule of Employee Benefit Plans [Line Items]
Defined Contribution Plan, Cost Recognized			$ 17.5	$ 23.3
CANADA | Minimum [Member]
Schedule of Employee Benefit Plans [Line Items]
Defined Contribution Plan Employer Matching Contribution Percent			3.00%
CANADA | Maximum [Member]
Schedule of Employee Benefit Plans [Line Items]
Defined Contribution Plan Employer Matching Contribution Percent			5.00%
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%

EMPLOYEE BENEFIT PLANS EMPLOYEE

EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS Pension Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Compensation and Retirement Disclosure [Abstract]
Defined Benefit Plan, Contributions by Employer	$ 500	$ 500	$ 1,500	$ 1,700
Service cost	1,113	912	3,442	2,712
Interest cost	991	1,172	3,064	3,486
Expected return on plan assets	(1,299)	(1,380)	(4,017)	(4,103)
Defined Benefit Plan, Actuarial Gain (Loss)	(4)	(14)	(12)	(43)
Net periodic benefit cost	$ 801	$ 690	$ 2,477	$ 2,052

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2015	Mar. 31, 2013	Sep. 30, 2015	Dec. 31, 2012	Jun. 30, 2013
Loss Contingencies [Line Items]
Loss Contingency, Accrual, Current					$ 3.9
Damages sought			$ 50
Loss Contingency, Damages Paid, Value	$ 35.8
Litigation Settlement, Amount	36.1
Loss Contingency, Damages Awarded, Value		$ 36.1		$ 36.1
Litigation Settlement Interest	$ 10.2

INCOME TAXES (Details)

INCOME TAXES (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Income Tax Contingency [Line Items]
Effective tax rate	27.40%	28.60%	28.12984%
Federal statutory rate		35.00%

OTHER FINANCIAL INFORMATION (De

OTHER FINANCIAL INFORMATION (Details) $ in Millions	Sep. 30, 2015USD ($)
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.375%
Convertible Senior Debentures Due in 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 344.9
Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 500

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Condensed Financial Information [Line Items]
Cash and cash equivalents	$ 132,852	$ 128,319	$ 110,368	$ 123,725
Trade accounts receivable, net	1,149,743	1,117,420
Inventories, net	844,955	819,502
Prepaid Expense and Other Assets, Current	167,287	146,352
Total current assets	2,366,090	2,350,338
Property, buildings and equipment, net	171,789	182,725
Intangible assets, net	388,988	429,840
Goodwill and other intangibles, net	1,666,218	1,735,440
Other assets	49,424	56,094
Total assets	4,642,509	4,754,437
Accounts payable	787,637	765,135
Short-term debt	44,419	46,787
Total current liabilities	1,016,777	1,063,872
Total stockholders' equity	1,762,795	1,928,652
Stockholders' Equity Attributable to Noncontrolling Interest	2,947	487
Total liabilities and stockholders' equity	4,642,509	4,754,437
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
Prepaid Expense and Other Assets, Current	18	12
Total current assets	18	12
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	3,294,404	3,304,914
Other assets	3,875	4,083
Total assets	3,298,297	3,309,009
Accounts payable	0	0
Short-term debt	0	0
Other Liabilities, Current	7,291	12,465
Total current liabilities	7,291	12,465
Intercompany payables, net	1,325,788	1,168,366
Long-term debt	180,534	177,638
Liabilities, Other than Long-term Debt, Noncurrent	21,889	21,888
Total stockholders' equity	1,762,795	1,928,652
Stockholders' Equity Attributable to Noncontrolling Interest	0	0
Total liabilities and stockholders' equity	3,298,297	3,309,009
Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Cash and cash equivalents	39,779	32,508	37,639	31,695
Trade accounts receivable, net	0	0
Inventories, net	401,669	373,938
Prepaid Expense and Other Assets, Current	121,802	144,282
Total current assets	563,250	550,728
Intercompany receivables, net	0	0
Property, buildings and equipment, net	57,722	56,735
Intangible assets, net	4,237	4,733
Goodwill and other intangibles, net	255,251	246,771
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	3,776,151	3,828,727
Other assets	12,262	12,844
Total assets	4,668,873	4,700,538
Accounts payable	454,216	445,680
Short-term debt	0	0
Other Liabilities, Current	54,027	113,746
Total current liabilities	508,243	559,426
Intercompany payables, net	621,470	637,849
Long-term debt	730,813	683,407
Liabilities, Other than Long-term Debt, Noncurrent	256,204	232,544
Total stockholders' equity	2,552,143	2,587,312
Stockholders' Equity Attributable to Noncontrolling Interest	0	0
Total liabilities and stockholders' equity	4,668,873	4,700,538
Non-Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Cash and cash equivalents	93,073	95,811	72,729	92,030
Trade accounts receivable, net	1,149,743	1,117,420
Inventories, net	443,286	445,564
Prepaid Expense and Other Assets, Current	123,134	147,268
Total current assets	1,809,236	1,806,063
Intercompany receivables, net	1,947,258	1,806,215
Property, buildings and equipment, net	114,067	125,990
Intangible assets, net	384,751	425,107
Goodwill and other intangibles, net	1,410,967	1,488,669
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Other assets	33,287	39,167
Total assets	5,699,566	5,691,211
Accounts payable	333,421	319,455
Short-term debt	44,419	46,787
Other Liabilities, Current	129,817	132,204
Total current liabilities	507,657	498,446
Intercompany payables, net	0	0
Long-term debt	543,358	505,385
Liabilities, Other than Long-term Debt, Noncurrent	133,086	141,538
Total stockholders' equity	4,518,412	4,546,329
Stockholders' Equity Attributable to Noncontrolling Interest	2,947	487
Total liabilities and stockholders' equity	5,699,566	5,691,211
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
Prepaid Expense and Other Assets, Current	(6,414)	(6,465)
Total current assets	(6,414)	(6,465)
Intercompany receivables, net	(1,947,258)	(1,806,215)
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	(7,070,555)	(7,133,641)
Other assets	0	0
Total assets	(9,024,227)	(8,946,321)
Accounts payable	0	0
Short-term debt	0	0
Other Liabilities, Current	(6,414)	(6,465)
Total current liabilities	(6,414)	(6,465)
Intercompany payables, net	(1,947,258)	(1,806,215)
Long-term debt	0	0
Liabilities, Other than Long-term Debt, Noncurrent	0	0
Total stockholders' equity	(7,070,555)	(7,133,641)
Stockholders' Equity Attributable to Noncontrolling Interest	0	0
Total liabilities and stockholders' equity	(9,024,227)	(8,946,321)
Consolidated Entities [Member]
Condensed Financial Information [Line Items]
Cash and cash equivalents	132,852	128,319	$ 110,368	$ 123,725
Trade accounts receivable, net	1,149,743	1,117,420
Inventories, net	844,955	819,502
Prepaid Expense and Other Assets, Current	238,540	285,097
Total current assets	2,366,090	2,350,338
Intercompany receivables, net	0	0
Property, buildings and equipment, net	171,789	182,725
Intangible assets, net	388,988	429,840
Goodwill and other intangibles, net	1,666,218	1,735,440
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Other assets	49,424	56,094
Total assets	4,642,509	4,754,437
Accounts payable	787,637	765,135
Short-term debt	44,419	46,787
Other Liabilities, Current	184,721	251,950
Total current liabilities	1,016,777	1,063,872
Intercompany payables, net	0	0
Long-term debt	1,454,705	1,366,430
Liabilities, Other than Long-term Debt, Noncurrent	411,179	395,970
Total stockholders' equity	1,762,795	1,928,652
Stockholders' Equity Attributable to Noncontrolling Interest	2,947	487
Total liabilities and stockholders' equity	$ 4,642,509	$ 4,754,437

CONDENSED CONSOLIDATED INCOME S

CONDENSED CONSOLIDATED INCOME STATEMENTS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Condensed Financial Information [Line Items]
Net sales	$ 1,923,899	$ 2,078,150	$ 5,656,947	$ 5,894,141
Cost of goods sold	1,543,113	1,655,787	4,526,836	4,685,257
Selling, general and administrative expense	258,151	271,697	797,980	815,869
Depreciation and amortization	16,287	17,418	48,347	50,976
Provision for income taxes	23,547	31,632	64,047	78,757
Net income (loss)	62,384	80,818	159,813	201,459
Less: Net (loss) income attributable to noncontrolling interest	(1,119)	2	(2,460)	(64)
Net income (loss) attributable to WESCO International, Inc.	63,503	80,816	162,273	201,523
Comprehensive Income:
Foreign currency translation adjustment	(95,377)	(63,794)	(183,634)	(67,271)
Comprehensive income attributable to WESCO International, Inc.	(31,874)	17,022	(21,361)	134,252
Parent Company [Member]
Condensed Financial Information [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal				(5,137)
Net sales		0	0	0
Cost of goods sold	0	0	0	0
Selling, general and administrative expense	5	0	22	2
Depreciation and amortization	0	0	0	0
Affiliate Costs	66,944	85,219	173,137	214,601
Interest Income (Expense), Net	(6,253)	(6,123)	(18,641)	(18,277)
Provision for income taxes	(1,698)	(1,722)	(5,339)	201,459
Net income (loss)	62,384	80,818	159,813	0
Less: Net (loss) income attributable to noncontrolling interest	0	0	0	201,459
Net income (loss) attributable to WESCO International, Inc.	62,384	80,818	159,813
Comprehensive Income:
Foreign currency translation adjustment	(95,377)	(63,794)	(183,634)	(67,271)
Comprehensive income attributable to WESCO International, Inc.	(32,993)	17,024	(23,821)	134,188
Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal				10,244
Net sales	876,098	932,948	2,600,150	2,656,619
Cost of goods sold	705,698	747,219	2,089,594	2,126,743
Selling, general and administrative expense	131,648	141,924	415,971	423,371
Depreciation and amortization	4,866	4,670	14,640	14,284
Affiliate Costs	48,419	62,611	131,074	164,826
Interest Income (Expense), Net	(19,681)	(18,765)	(55,561)	(55,854)
Provision for income taxes	3,988	5,733	6,976	190,949
Net income (loss)	58,636	77,248	148,482	0
Less: Net (loss) income attributable to noncontrolling interest	0	0	0	190,949
Net income (loss) attributable to WESCO International, Inc.	58,636	77,248	148,482
Comprehensive Income:
Foreign currency translation adjustment	(95,377)	(63,794)	(183,634)	(67,271)
Comprehensive income attributable to WESCO International, Inc.	(36,741)	13,454	(35,152)	123,678
Non-Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal				73,650
Net sales	1,077,255	1,174,935	3,144,759	3,323,237
Cost of goods sold	866,869	938,301	2,525,204	2,644,229
Selling, general and administrative expense	126,498	129,773	381,987	392,496
Depreciation and amortization	11,421	12,748	33,707	36,692
Affiliate Costs	0	0	0	0
Interest Income (Expense), Net	(5,517)	(4,090)	14,278	12,308
Provision for income taxes	21,257	27,621	62,410	188,478
Net income (loss)	56,727	70,582	155,729	(64)
Less: Net (loss) income attributable to noncontrolling interest	(1,119)	2	(2,460)	188,542
Net income (loss) attributable to WESCO International, Inc.	57,846	70,580	158,189
Comprehensive Income:
Foreign currency translation adjustment	(95,377)	(63,794)	(183,634)	(67,271)
Comprehensive income attributable to WESCO International, Inc.	(37,531)	6,786	(25,445)	121,271
Consolidation, Eliminations [Member]
Condensed Financial Information [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal				0
Net sales	(29,454)	(29,733)	(87,962)	(85,715)
Cost of goods sold	(29,454)	(29,733)	(87,962)	(85,715)
Selling, general and administrative expense	0	0	0	0
Depreciation and amortization	0	0	0	0
Affiliate Costs	(115,363)	(147,830)	(304,211)	(379,427)
Interest Income (Expense), Net	0	0	0	0
Provision for income taxes	0	0	0	(379,427)
Net income (loss)	(115,363)	(147,830)	(304,211)	0
Less: Net (loss) income attributable to noncontrolling interest	0	0	0	(379,427)
Net income (loss) attributable to WESCO International, Inc.	(115,363)	(147,830)	(304,211)
Comprehensive Income:
Foreign currency translation adjustment	190,754	127,588	367,268	134,542
Comprehensive income attributable to WESCO International, Inc.	75,391	(20,242)	63,057	(244,885)
Consolidated Entities [Member]
Condensed Financial Information [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal				78,757
Net sales	1,923,899	2,078,150	5,656,947	5,894,141
Cost of goods sold	1,543,113	1,655,787	4,526,836	4,685,257
Selling, general and administrative expense	258,151	271,697	797,980	815,869
Depreciation and amortization	16,287	17,418	48,347	50,976
Affiliate Costs	0	0	0	0
Interest Income (Expense), Net	20,417	(20,798)	(59,924)	(61,823)
Provision for income taxes	23,547	31,632	64,047	201,459
Net income (loss)	62,384	80,818	159,813	(64)
Less: Net (loss) income attributable to noncontrolling interest	(1,119)	2	(2,460)	201,523
Net income (loss) attributable to WESCO International, Inc.	63,503	80,816	162,273
Comprehensive Income:
Foreign currency translation adjustment	(95,377)	(63,794)	(183,634)	(67,271)
Comprehensive income attributable to WESCO International, Inc.	$ (31,874)	$ 17,022	$ (21,361)	$ 134,252

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Condensed Financial Information [Line Items]
Payments for (Proceeds from) Other Investing Activities	$ 1,791	$ 5,444
Net cash (used) provided by operating activities	175,964	139,820
Investing Activities:
Capital expenditures	(16,242)	(16,036)
Acquisition payments	(68,502)	(138,805)
Net cash used in investing activities	(82,953)	(149,397)
Financing Activities:
Payments for Repurchase of Common Stock	(155,775)	(6,931)
Proceeds from (Payments for) Other Financing Activities	(11,253)	(2,381)
Net cash used in financing activities	(73,288)	(4,410)
Effect of exchange rate changes on cash and cash equivalents	(15,190)	630
Net change in cash and cash equivalents	4,533	(13,357)
Cash and cash equivalents at the beginning of period	128,319	123,725
Cash and cash equivalents at the end of period	132,852	110,368
Parent Company [Member]
Condensed Financial Information [Line Items]
Payments for (Proceeds from) Other Investing Activities	0	0
Net cash (used) provided by operating activities	(3,332)	(5,202)
Investing Activities:
Capital expenditures	0	0
Acquisition payments	0	0
Net cash used in investing activities	0	0
Financing Activities:
Borrowings	157,422	6,517
Repayments	0	(675)
Payments for Repurchase of Common Stock	(154,090)	(640)
Proceeds from (Payments for) Other Financing Activities	0	0
Net cash used in financing activities	3,332	5,202
Effect of exchange rate changes on cash and cash equivalents	0	0
Net change in cash and cash equivalents	0	0
Cash and cash equivalents at the beginning of period	0	0
Cash and cash equivalents at the end of period	0	0
Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Payments for (Proceeds from) Other Investing Activities	(157,422)	(5,842)
Net cash (used) provided by operating activities	210,270	68,291
Investing Activities:
Capital expenditures	(12,137)	(10,811)
Acquisition payments	(68,502)	(42,132)
Net cash used in investing activities	(238,061)	(58,785)
Financing Activities:
Borrowings	936,352	645,411
Repayments	(888,352)	(640,411)
Payments for Repurchase of Common Stock	0	0
Proceeds from (Payments for) Other Financing Activities	(12,938)	(8,562)
Net cash used in financing activities	35,062	(3,562)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net change in cash and cash equivalents	7,271	5,944
Cash and cash equivalents at the beginning of period	32,508	31,695
Cash and cash equivalents at the end of period	39,779	37,639
Non-Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Proceeds from Sale of Productive Assets	1,791	5,444
Net cash (used) provided by operating activities	(30,974)	76,731
Investing Activities:
Capital expenditures	(4,105)	(5,225)
Acquisition payments	0	(96,673)
Net cash used in investing activities	(2,314)	(96,454)
Financing Activities:
Borrowings	359,546	316,462
Repayments	(313,806)	(316,560)
Payments for Repurchase of Common Stock	0	0
Proceeds from (Payments for) Other Financing Activities	0	(110)
Net cash used in financing activities	45,740	(208)
Effect of exchange rate changes on cash and cash equivalents	(15,190)	630
Net change in cash and cash equivalents	(2,738)	(19,301)
Cash and cash equivalents at the beginning of period	95,811	92,030
Cash and cash equivalents at the end of period	93,073	72,729
Consolidation, Eliminations [Member]
Condensed Financial Information [Line Items]
Payments for (Proceeds from) Other Investing Activities	157,422	5,842
Net cash (used) provided by operating activities	0	0
Investing Activities:
Capital expenditures	0	0
Acquisition payments	0	0
Net cash used in investing activities	157,422	5,842
Financing Activities:
Borrowings	(157,422)	(6,517)
Repayments	0	(675)
Payments for Repurchase of Common Stock	0	0
Proceeds from (Payments for) Other Financing Activities	0	0
Net cash used in financing activities	(157,422)	(5,842)
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
Consolidated Entities [Member]
Condensed Financial Information [Line Items]
Proceeds from Sale of Productive Assets	1,791	5,444
Net cash (used) provided by operating activities	175,964	139,820
Investing Activities:
Capital expenditures	(16,242)	(16,036)
Acquisition payments	(68,502)	(138,805)
Net cash used in investing activities	(82,953)	(149,397)
Financing Activities:
Borrowings	1,295,898	961,873
Repayments	(1,202,158)	(956,971)
Payments for Repurchase of Common Stock	(154,090)	(640)
Proceeds from (Payments for) Other Financing Activities	(12,938)	(8,672)
Net cash used in financing activities	(73,288)	(4,410)
Effect of exchange rate changes on cash and cash equivalents	(15,190)	630
Net change in cash and cash equivalents	4,533	(13,357)
Cash and cash equivalents at the beginning of period	128,319	123,725
Cash and cash equivalents at the end of period	$ 132,852	$ 110,368

Subsequent Events (Details)

Subsequent Events (Details) - Needham Electric Supply Corporation [Member] $ in Millions	9 Months Ended
	Sep. 30, 2015USD ($)
Subsequent Event [Line Items]
Business Acquisition, Effective Date of Acquisition	Oct. 30, 2015
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period	$ 115