10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

þ	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the quarterly period ended September 30, 2017

or

o	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the transition period from to

Commission File Number: 001-14989

WESCO International, Inc.

(Exact name of registrant as specified in its charter)

Delaware (State or other jurisdiction of incorporation or organization)	25-1723342 (I.R.S. Employer Identification No.)
225 West Station Square Drive Suite 700 Pittsburgh, Pennsylvania (Address of principal executive offices)	15219 (Zip Code)

(412) 454-2200

(Registrant's telephone number, including area code)

Not applicable.

(Former name, former address and former fiscal year, if changed since last report) 

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for at least the past 90 days.             Yes þ No o

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).

Yes þ No o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

Large accelerated filer þ	Accelerated filer o
Non-accelerated filer o (Do not check if a smaller reporting company)	Smaller reporting company o
	Emerging growth company o
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes o No þ

As of November 2, 2017, 47,002,338 shares of common stock, $0.01 par value, of the registrant were outstanding.

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

QUARTERLY REPORT ON FORM 10-Q

Table of Contents

	Page
PART I—FINANCIAL INFORMATION
Item 1. Financial Statements.	2
Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations.	22
Item 3. Quantitative and Qualitative Disclosures About Market Risk.	31
Item 4. Controls and Procedures.	31
PART II—OTHER INFORMATION
Item 1. Legal Proceedings.	32
Item 2. Unregistered Sales of Equity Securities and Use of Proceeds.	32
Item 1A. Risk Factors.	32
Item 6. Exhibits.	33
Signatures	34
EXHIBITS

1

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

PART I—FINANCIAL INFORMATION

Item 1. Financial Statements.

The interim financial information required by this item is set forth in the Condensed Consolidated Financial Statements and Notes thereto in this Quarterly Report on Form 10-Q, as follows:

	Page
Condensed Consolidated Balance Sheets (unaudited)	3
Condensed Consolidated Statements of Income (Loss) and Comprehensive Income (Loss) (unaudited)	4
Condensed Consolidated Statements of Cash Flows (unaudited)	5
Notes to Condensed Consolidated Financial Statements (unaudited)	6

2

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED BALANCE SHEETS

(In thousands of dollars, except share data)

(unaudited)

	As of
	September 30, 2017			December 31, 2016
Assets
Current assets:
Cash and cash equivalents	$	94,083		$	110,131
Trade accounts receivable, net of allowance for doubtful accounts of $24,240 and $22,007 in 2017 and 2016, respectively	1,236,612			1,034,402
Other accounts receivable	82,588			85,019
Inventories	925,049			821,441
Prepaid expenses and other current assets (Note 2)	71,795			52,085
Total current assets	2,410,127			2,103,078
Property, buildings and equipment, net of accumulated depreciation of $274,643 and $259,126 in 2017 and 2016, respectively	157,591			157,607
Intangible assets, net of accumulated amortization of $214,225 and $178,813 in 2017 and 2016, respectively	378,153			393,362
Goodwill (Note 2)	1,776,918			1,730,950
Other assets	41,679			46,844
Total assets	$	4,764,468		$	4,431,841
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable	$	838,427		$	684,721
Accrued payroll and benefit costs	50,848			49,250
Short-term debt	39,712			20,920
Current portion of long-term debt	1,213			1,218
Bank overdrafts	26,150			29,384
Other current liabilities (Note 2)	87,143			88,306
Total current liabilities	1,043,493			873,799
Long-term debt, net of debt discount and debt issuance costs of $14,302 and $17,278 in 2017 and 2016, respectively	1,368,301			1,363,135
Deferred income taxes (Note 2)	179,630			168,245
Other noncurrent liabilities	65,811			63,031
Total liabilities	$	2,657,235		$	2,468,210
Commitments and contingencies (Note 8)
Stockholders’ equity:
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding	—			—
Common stock, $.01 par value; 210,000,000 shares authorized, 59,036,037 and 58,817,781 shares issued and 46,999,652 and 48,611,497 shares outstanding in 2017 and 2016, respectively	590			588
Class B nonvoting convertible common stock, $.01 par value; 20,000,000 shares authorized, 4,339,431 issued and no shares outstanding in 2017 and 2016, respectively	43			43
Additional capital	995,670			986,020
Retained earnings (Note 2)	2,056,961			1,914,757
Treasury stock, at cost; 16,375,816 and 14,545,715 shares in 2017 and 2016, respectively	(647,138		)	(542,537		)
Accumulated other comprehensive loss (Note 2)	(295,622		)	(391,971		)
Total WESCO International, Inc. stockholders' equity	2,110,504			1,966,900
Noncontrolling interests	(3,271		)	(3,269		)
Total stockholders’ equity	2,107,233			1,963,631
Total liabilities and stockholders’ equity	$	4,764,468		$	4,431,841

The accompanying notes are an integral part of the condensed consolidated financial statements.

3

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) AND COMPREHENSIVE INCOME (LOSS)

(In thousands of dollars, except per share data)

(unaudited)

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2017			2016			2017			2016
Net sales	$	2,000,159		$	1,855,212		$	5,682,375		$	5,542,755
Cost of goods sold (excluding depreciation and
amortization)	1,614,814			1,490,173			4,580,896			4,443,079
Selling, general and administrative expenses	280,021			255,547			814,275			799,356
Depreciation and amortization	16,074			16,937			47,758			50,269
Income from operations	89,250			92,555			239,446			250,051
Interest expense, net	17,311			20,792			50,847			59,073
Loss on debt redemption	—			123,933			—			123,933
Income (loss) before income taxes	71,939			(52,170		)	188,599			67,045
Provision for income taxes	18,363			(21,149		)	47,684			13,678
Net income (loss)	53,576			(31,021		)	140,915			53,367
Less: Net (loss) income attributable to noncontrolling interests	(99		)	590			(3		)	(876		)
Net income (loss) attributable to WESCO International, Inc.	$	53,675		$	(31,611	)	$	140,918		$	54,243
Other comprehensive income (loss):
Foreign currency translation adjustments	51,148			(13,993		)	96,097			66,512
Post retirement benefit plan adjustment	—			—			252			(16		)
Comprehensive income (loss) attributable to WESCO International, Inc.	$	104,823		$	(45,604	)	$	237,267		$	120,739
Earnings (loss) per share attributable to WESCO International, Inc.
Basic	$	1.13		$	(0.73	)	$	2.93		$	1.27
Diluted	$	1.12		$	(0.73	)	$	2.90		$	1.13

The accompanying notes are an integral part of the condensed consolidated financial statements.

4

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands of dollars)

(unaudited)

	Nine Months Ended
	September 30,
	2017			2016
Operating activities:
Net income	$	140,915		$	53,367
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	47,758			50,269
Deferred income taxes	8,433			(21,842		)
Loss on debt redemption	—			123,933
Other operating activities, net	12,617			11,228
Changes in assets and liabilities:
Trade accounts receivable, net	(174,667		)	(3,075		)
Other accounts receivable	4,421			15,524
Inventories	(86,736		)	(7,651		)
Prepaid expenses and other assets	(8,515		)	(8,625		)
Accounts payable	138,348			(30,289		)
Accrued payroll and benefit costs	2,383			(2,648		)
Other current and noncurrent liabilities	(3,846		)	36,997
Net cash provided by operating activities	81,111			217,188
Investing activities:
Acquisition payments, net of cash acquired	—			(50,745		)
Capital expenditures	(15,970		)	(13,183		)
Other investing activities	3,490			(3,885		)
Net cash used in investing activities	(12,480		)	(67,813		)
Financing activities:
Proceeds from issuance of short-term debt	130,890			89,847
Repayments of short-term debt	(114,972		)	(96,535		)
Proceeds from issuance of long-term debt	1,079,718			1,731,715
Repayments of long-term debt	(1,076,718		)	(1,915,545		)
Repurchases of common stock (Note 6)	(106,702		)	(4,073		)
Other financing activities, net	(4,380		)	(3,494		)
Net cash used in financing activities	(92,164		)	(198,085		)
Effect of exchange rate changes on cash and cash equivalents	7,485			1,268
Net change in cash and cash equivalents	(16,048		)	(47,442		)
Cash and cash equivalents at the beginning of period	110,131			160,279
Cash and cash equivalents at the end of period	$	94,083		$	112,837

The accompanying notes are an integral part of the condensed consolidated financial statements.

5

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(unaudited)

1. ORGANIZATION

WESCO International, Inc. ("WESCO International") 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 manufacturer (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 approximately 75,000 active customers globally, through approximately 500 full service branches and ten distribution centers located primarily in the United States, Canada and Mexico, with operations in 14 additional countries.

2. 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 2016 Annual Report on Form 10-K as filed with the SEC on February 22, 2017. The Condensed Consolidated Balance Sheet at December 31, 2016 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, 2017, the unaudited Condensed Consolidated Statements of Income and Comprehensive Income for the three and nine months ended September 30, 2017 and 2016, respectively, and the unaudited Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2017 and 2016, 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.

Revision of Prior Period Financial Statements

In the third quarter of 2017, management determined that the Company's income taxes receivable and payable and other tax account balances were overstated as of December 31, 2016 by a cumulative net amount of $46.4 million, which related to multiple prior periods. The Company also identified a $10.2 million understatement related to deferred income taxes and goodwill. In accordance with Staff Accounting Bulletin (“SAB”) No. 99, Materiality, and SAB No. 108, Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements, management concluded that these misstatements are not material to the Company's previously issued annual and interim financial statements. Correcting the effected financial statement line items in the quarterly period ended September 30, 2017 would materially misstate the condensed consolidated financial information presented herein. Accordingly, the Condensed Consolidated Balance Sheet at December 31, 2016 in this Quarterly Report on Form 10-Q has been revised. There was an immaterial effect on the Condensed Consolidated Statements of Income and Comprehensive Income for the three and nine months ended September 30, 2016, and no effect on the Condensed Consolidated Statements of Cash Flows for the respective periods presented herein. Periods not presented herein will be revised, as applicable, in future filings.

6

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

The following table presents the effects on the financial statement line items that were revised:

	December 31, 2016
	As Reported			Adjustment			As Revised
	(In thousands)
Prepaid expenses and other current assets	$	121,464		$	(69,379	)	$	52,085
Total current assets	2,172,457			(69,379		)	2,103,078
Goodwill	1,720,714			10,236			1,730,950
Total assets	4,490,984			(59,143		)	4,431,841
Other current liabilities	111,304			(22,998		)	88,306
Total current liabilities	896,797			(22,998		)	873,799
Deferred income taxes	158,009			10,236			168,245
Total liabilities	2,480,972			(12,762		)	2,468,210
Retained earnings	1,956,532			(41,775		)	1,914,757
Accumulated other comprehensive loss	(387,365		)	(4,606		)	(391,971		)
Total stockholders' equity	2,010,012			(46,381		)	1,963,631
Total liabilities and stockholders' equity	4,490,984			(59,143		)	4,431,841

Recently Adopted Accounting Pronouncements

In March 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, which simplifies several aspects of accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments in this ASU affect all entities that issue share-based payment awards to their employees. The Company adopted this ASU in the first quarter of 2017. The amendment related to the recognition of excess tax benefits and deficiencies was applied prospectively and, as disclosed in Note 9, lowered the Company's effective tax rate for the nine months ended September 30, 2017. The amendment related to the presentation of excess tax benefits on the statement of cash flows was also applied prospectively, and did not have a material impact on WESCO's cash flows. The other amendments, which were adopted by the Company according to the respective transition requirements, had no impact on the consolidated financial statements and notes thereto.

In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory. The purpose of ASU 2016-16 is to simplify the income tax accounting of an intra-entity transfer of an asset other than inventory and to record its effect when the transfer occurs. The Company early adopted this ASU on a modified retrospective basis in the first quarter of 2017. The adoption of this ASU did not have a material impact on WESCO's financial position and it had no impact on its results of operations or cash flows.

Recently Issued Accounting Pronouncements

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. During 2016, the FASB issued four ASUs that address implementation issues and correct or improve certain aspects of the new revenue recognition guidance, including ASU 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross versus Net), ASU 2016-10, Identifying Performance Obligations and Licensing, ASU 2016-12, Narrow-Scope Improvements and Practical Expedients and ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers. These ASUs do not change the core principles in the revenue recognition standard outlined above. The Company has developed a multiphase plan and established a cross-functional team to evaluate and implement the new standard. Management has completed the diagnostic phase, which involved reviewing various customer contracts and comparing current

7

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

accounting to the requirements of the new standard. Currently management is evaluating the new disclosure requirements and identifying and implementing appropriate changes to its business processes and controls to support recognition and disclosure under the new standard. The new standard will be adopted in the first quarter of 2018 and the Company expects to use the modified retrospective approach. Management will continue to evaluate the impact that this pronouncement may have on WESCO's consolidated financial statements and notes thereto.

In February 2016, the FASB issued ASU 2016-02, Leases, a comprehensive new standard that amends various aspects of existing accounting guidance for leases, including the recognition of a right-of-use asset and a lease liability on the balance sheet and disclosing key information about leasing arrangements. This guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The new leasing standard requires modified retrospective transition, which requires application of the new guidance at the beginning of the earliest comparative period presented in the year of adoption. Management is currently evaluating the impact of this new standard on WESCO's consolidated financial statements and notes thereto.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which introduces new guidance for the accounting for credit losses on certain financial instruments. The amendments in ASU 2016-13 are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years and early adoption is permitted. Management is currently evaluating the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force). This ASU provides guidance on eight specific cash flow issues where there is diversity in practice. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. Management is currently evaluating the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In January 2017, the FASB issued ASU 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, which eliminates Step 2 from the goodwill impairment test. Under the amendments in this update, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. An entity should apply the amendments in this ASU on a prospective basis. This guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Management has not yet evaluated the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In March 2017, the FASB issued ASU 2017-07, Compensation—Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. Presently, net benefit cost is reported as an employee cost within operating income (or capitalized into assets when appropriate). This amendment requires the bifurcation of net benefit cost. The service component will be presented with other employee compensation costs in operating income (or capitalized in assets). The other components will be reported separately outside of operations, and will not be eligible for capitalization. This guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. Management has not yet evaluated the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting, which clarifies when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new guidance, modification accounting is required only if the fair value, the vesting conditions, or the classification of the award (as equity or liability) changes as a result of the change in terms or conditions. The guidance is effective prospectively for all companies for annual periods beginning on or after December 15, 2017. Early adoption is permitted. Management has not yet evaluated the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

Other pronouncements issued by the FASB or other authoritative accounting standards groups with future effective dates are either not applicable or are not expected to be significant to WESCO’s financial position, results of operations or cash flows.

Fair Value of Financial Instruments

The Company’s financial instruments consist of cash and cash equivalents, accounts receivable, accounts payable and other accrued liabilities, and outstanding indebtedness. The reported carrying amounts of WESCO’s financial instruments approximate their fair values. The Company uses a market approach to fair value all of its debt instruments, utilizing quoted

8

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

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.

3. ACQUISITIONS

On March 14, 2016, WESCO Distribution, Inc. ("WESCO Distribution") completed the acquisition of Atlanta Electrical Distributors, LLC ("AED"), an Atlanta-based electrical distributor focused on the construction and MRO markets from five locations in Georgia with approximately $85 million in annual sales. WESCO Distribution funded the purchase price paid at closing with borrowings under its 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. In addition to the cash paid at closing, the purchase price included a contingent payment that may be earned upon the achievement of certain financial performance targets over three consecutive one year periods. The fair value of the contingent consideration was determined using a probability-weighted outcome analysis and Level 3 inputs such as internal forecasts. This amount was accrued at the maximum potential payout under the terms of the purchase agreement. The fair value of intangibles was estimated by management and the allocation resulted in intangible assets of $21.8 million and goodwill of $30.0 million. The intangible assets include customer relationships of $15.8 million amortized over 13 and 14 years, a trademark of $6.0 million amortized over 13 years, and non-compete agreements of less than $0.1 million amortized over 5 years. No residual value was estimated for the intangible assets being amortized. The majority of goodwill is deductible for tax purposes.

4. GOODWILL

The following table sets forth the changes in the carrying value of goodwill:

	Nine Months Ended
	September 30, 2017		September 30, 2016
	(In thousands)
Beginning balance January 1(1)	$	1,730,950	$	1,681,662
Foreign currency exchange rate changes	45,968		34,799
Adjustments to goodwill for acquisitions (2)	—		19,201
Ending balance September 30	$	1,776,918	$	1,735,662

⁽¹⁾ As described in Note 2, the Condensed Consolidated Balance Sheet at December 31, 2016 has been revised to correct certain financial statement line items, including goodwill.

⁽²⁾ For the nine months ended September 30, 2016, adjustments relate to goodwill resulting from the preliminary allocation of the AED purchase price to the respective assets acquired and liabilities assumed, partially offset by an adjustment to goodwill related to deferred income taxes.

5. 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.

9

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

During the three and nine months endedSeptember 30, 2017 and 2016, WESCO granted the following stock-settled stock appreciation rights, restricted stock units and performance-based awards at the following weighted-average fair values:

	Three Months Ended				Nine Months Ended
	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Stock-settled stock appreciation rights granted	12,076		1,745		455,807		709,999
Weighted-average fair value	$	15.74	$	16.68	$	20.52	$	12.91
Restricted stock units granted	2,313		—		100,993		143,305
Weighted-average fair value	$	57.30	$	—	$	71.33	$	42.45
Performance-based awards granted	—		—		39,978		91,768
Weighted-average fair value	$	—	$	—	$	76.63	$	47.00

The fair value of stock-settled stock appreciation rights was estimated using the following weighted-average assumptions:

	Three Months Ended				Nine Months Ended
	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Risk free interest rate	1.8	%	1.3	%	1.9	%	1.2	%
Expected life (in years)	5		5		5		5
Expected volatility	28	%	31	%	29	%	32	%

The risk-free interest rate is based on the U.S. Treasury Daily Yield Curve rate 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, 2017:

	Awards		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In years)	Aggregate Intrinsic Value (In thousands)
Outstanding at December 31, 2016	2,439,487		$	52.62
Granted	455,807		71.21
Exercised	(472,873	)	42.41
Forfeited	(143,506	)	66.21
Outstanding at September 30, 2017	2,278,915		57.60		6.4	$	18,344
Exercisable at September 30, 2017	1,359,744		$	56.71	4.8	$	12,212

10

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

The following table sets forth a summary of time-based restricted stock units and related information for the nine months ended September 30, 2017:

	Awards		Weighted- Average Fair Value
Unvested at December 31, 2016	257,096		$	57.47
Granted	100,993		71.33
Vested	(43,780	)	85.13
Forfeited	(18,022	)	55.96
Unvested at September 30, 2017	296,287		$	58.20

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, 2017:

	Awards		Weighted- Average Fair Value
Unvested at December 31, 2016	149,320		$	60.36
Granted	39,978		76.63
Vested	—		—
Forfeited	(39,650	)	77.40
Unvested at September 30, 2017	149,648		$	60.19

The fair value of the performance shares granted during the nine months ended September 30, 2017 and 2016 was estimated using the following weighted-average assumptions:

	Nine Months Ended
	September 30, 2017			September 30, 2016
Grant date share price	$	71.65		$	42.44
WESCO expected volatility	29		%	26		%
Peer group median volatility	24		%	24		%
Risk-free interest rate	1.5		%	0.9		%
Correlation of peer company returns	114		%	122		%

The unvested performance-based awards in the table above include 74,824 shares in which vesting of the ultimate number of shares 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 74,824 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 $3.5 million and $3.4 million of non-cash stock-based compensation expense, which is included in selling, general and administrative expenses, for the three months ended September 30, 2017 and 2016, respectively. WESCO recognized $11.3 million and $10.4 million of non-cash stock-based compensation expense, which is included in selling, general and administrative expenses, for the nine months ended September 30, 2017 and 2016, respectively. As of September 30, 2017, there was $22.6 million of total unrecognized compensation cost related to non-vested stock-based compensation arrangements for all awards previously made, of which approximately $3.7 million is expected to be recognized over the remainder of 2017, $11.4 million in 2018, $6.7 million in 2019 and $0.8 million in 2020.

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NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

6. EARNINGS PER SHARE

Basic earnings per share is computed by dividing net income attributable to WESCO International by the weighted-average number of common shares outstanding during the periods. Diluted earnings per share is computed by dividing net income attributable to WESCO International 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 equity awards and contingently convertible debt.

The following table sets forth the details of basic and diluted earnings per share:

	Three Months Ended					Nine Months Ended
	September 30,					September 30,
(In thousands, except per share data)	2017		2016			2017		2016
Net income (loss) attributable to WESCO International, Inc.	$	53,675	$	(31,611	)	$	140,918	$	54,243
Weighted-average common shares outstanding used in computing basic earnings per share	47,415		43,378			48,134		42,611
Common shares issuable upon exercise of dilutive equity awards	389		511			508		519
Common shares issuable from contingently convertible debentures (see below for basis of calculation)	—		4,851			—		4,908
Weighted-average common shares outstanding and common share equivalents, diluted	47,804		48,740			48,642		48,038
Weighted-average common shares outstanding and common share equivalents used in computing diluted earnings per share	47,804		43,378			48,642		48,038
Earnings (loss) per share attributable to WESCO International, Inc.
Basic	$	1.13	$	(0.73	)	$	2.93	$	1.27
Diluted	$	1.12	$	(0.73	)	$	2.90	$	1.13

For the three and nine months endedSeptember 30, 2017, the computation of diluted earnings per share attributable to WESCO International, Inc. excluded stock-based awards of approximately 1.5 million and 1.3 million, respectively. For the three and nine months endedSeptember 30, 2016, the computation of diluted (loss) earnings per share attributable to WESCO International, Inc. excluded stock-based awards of approximately 1.3 million. These amounts were excluded because their effect would have been antidilutive.

Because of WESCO’s previous obligation to settle the par value of the 6.0% Convertible Senior Debentures due 2029 (the "2029 Debentures") in cash upon conversion, WESCO was 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 exceeded the conversion price of the debentures. Only the number of shares that would have been issuable under the treasury stock method of accounting for share dilution were included, which was based upon the amount by which the average stock price exceeded the conversion price. The conversion price of the 2029 Debentures was $28.87 and the maximum amount of share dilution was limited to 11,951,932 shares. Since the 2029 Debentures were redeemed on September 15, 2016, there was no dilution from contingently convertible debentures for the three and nine months endedSeptember 30, 2017. As a result of the net loss attributable to WESCO International, Inc. for the three months ended September 30, 2016, dilutive shares were not included in the calculation of diluted loss per share because their effect was antidilutive. For the nine months ended September 30, 2016, the effect of the 2029 Debentures on diluted earnings per share attributable to WESCO International, Inc. was a decrease of $0.13.

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. As of December 31, 2016, WESCO had repurchased 2,468,576 shares of the Company's common stock for $150.0 million under this repurchase authorization. During the three months ended June 30, 2017, the Company repurchased 804,291 shares under the repurchase authorization for $50.0 million. On August 7, 2017, the Company entered into an accelerated stock repurchase agreement (the "ASR Transaction") with a financial institution to repurchase additional shares of its common stock. In exchange for an up-front cash payment of $50.0 million, the Company received 974,246 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 the Company's revolving credit facility and

12

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NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

accounts receivable securitization facility. For purposes of computing earnings per share, share repurchases have been reflected as a reduction to common shares outstanding on the respective delivery dates.

7. 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 matches contributions made by employees at an amount equal to 50% of participants' total monthly contributions up to a maximum of 6% of eligible compensation. For Canadian participants, WESCO makes contributions in amounts ranging from 3% to 5% of the participants' eligible compensation based on years of continuous service. WESCO may also make, subject to the Board of Directors' approval, a discretionary contribution to the defined contribution retirement savings plan covering U.S. participants if certain predetermined profit levels are attained. For the nine months ended September 30, 2017 and 2016, WESCO incurred charges of $20.3 million and $18.1 million, respectively, for all such plans. Contributions are made in cash to employee retirement savings plan accounts. The deferred compensation plan is an unfunded plan. As of September 30, 2017 and December 31, 2016, the Company's obligation under the deferred compensation plan was $23.4 million and $21.7 million, respectively. 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 defined benefit plans:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
(In thousands of dollars)	2017			2016			2017			2016
Service cost	$	1,118		$	977		$	3,234		$	2,889
Interest cost	1,007			979			2,915			2,898
Expected return on plan assets	(1,432		)	(1,353		)	(4,144		)	(4,004		)
Recognized actuarial gain	(51		)	(10		)	(149		)	(31		)
Net periodic benefit cost	$	642		$	593		$	1,856		$	1,752

During the three and nine months endedSeptember 30, 2017, there were no employer contributions to the defined benefit plans. During the three and nine months endedSeptember 30, 2016, the Company made aggregate cash contributions of $0.5 million and $1.4 million, respectively, to the defined benefit plans.

8. COMMITMENTS AND CONTINGENCIES

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 is undergoing a compliance audit in the State of Delaware concerning the identification, reporting and escheatment of unclaimed or abandoned property. The third party auditor conducting the audit on behalf of the State has completed the audit fieldwork and provided a draft of its preliminary findings to the Company and the State for review. A final report is expected to be issued at some point in the future. 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, and is evaluating its alternatives under applicable laws and regulations. If the Company and State do not reach resolution after further discussion, the State may issue 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 is cooperating with the government investigation. The Company

13

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NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

cannot predict the outcome or impact of the matter at this time, but could be subject to fines, penalties or other adverse consequences. The Company has recorded a liability for the matter based on the facts currently known to the Company.

9. INCOME TAXES

The effective tax rate for the three and nine months endedSeptember 30, 2017 was 25.5% and 25.3%, respectively. The effective tax rate for the three and nine months endedSeptember 30, 2016 was 40.5% and 20.4%, respectively. The effective tax rates for the three and nine months endedSeptember 30, 2016 were impacted by the redemption of the 2029 Debentures on September 15, 2016. WESCO’s effective tax rate is typically lower than the federal statutory rate of 35% due to benefits resulting from the tax effect of intercompany financing and lower tax rates on foreign earnings, which are partially offset by nondeductible expenses and state taxes. The current year's effective tax rate is impacted by favorable discrete items, including a benefit from the exercise and vesting of stock-based awards, as well as the mix of income earned in jurisdictions with lower tax rates.

The total amount of unrecognized tax benefits was reduced by $1.6 million during the nine months ended September 30, 2017 to $4.6 million due to the expiration of statutes of limitation and the settlement of state audits. At September 30, 2017, the amount of unrecognized tax benefits that could affect the effective tax rate if recognized in the consolidated financial statements was $6.0 million. Within the next twelve months, it is reasonably possible that the amount of unrecognized tax benefits will decrease by approximately $0.2 million due to the expiration of statutes of limitation and the settlement of state audits. Of this amount, $0.2 million could impact the effective tax rate.

14

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NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

10. CONDENSED CONSOLIDATING FINANCIAL INFORMATION

WESCO Distribution has outstanding $500 million in aggregate principal amount of 5.375% Senior Notes due 2021 (the "2021 Notes") and $350 million in aggregate principal amount of 5.375% Senior Notes due 2024 (the "2024 Notes"). The 2021 Notes and 2024 Notes are unsecured senior obligations of WESCO Distribution and are fully and unconditionally guaranteed on a senior unsecured basis by WESCO International.

Condensed consolidating financial information for WESCO International, WESCO Distribution and the non-guarantor subsidiaries is presented in the following tables.

	Condensed Consolidating Balance Sheet
	September 30, 2017
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.		Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Cash and cash equivalents	$	—	$	45,775	$	48,308		$	—		$	94,083
Trade accounts receivable, net	—		—		1,236,612			—			1,236,612
Inventories	—		403,752		521,297			—			925,049
Prepaid expenses and other current assets	13,642		42,130		203,991			(105,380		)	154,383
Total current assets	13,642		491,657		2,010,208			(105,380		)	2,410,127
Intercompany receivables, net	—		—		2,141,945			(2,141,945		)	—
Property, buildings and equipment, net	—		50,191		107,400			—			157,591
Intangible assets, net	—		2,932		375,221			—			378,153
Goodwill	—		257,623		1,519,295			—			1,776,918
Investments in affiliates	3,817,521		4,228,307		—			(8,045,828		)	—
Other assets	—		18,615		23,064			—			41,679
Total assets	$	3,831,163	$	5,049,325	$	6,177,133		$	(10,293,153	)	$	4,764,468
Accounts payable	$	—	$	443,675	$	394,752		$	—		$	838,427
Short-term debt	—		—		39,712			—			39,712
Other current liabilities	—		117,701		153,033			(105,380		)	165,354
Total current liabilities	—		561,376		587,497			(105,380		)	1,043,493
Intercompany payables, net	1,707,926		434,019		—			(2,141,945		)	—
Long-term debt, net	—		968,361		399,940			—			1,368,301
Other noncurrent liabilities	12,733		61,635		171,073			—			245,441
Total WESCO International, Inc. stockholders' equity	2,110,504		3,023,934		5,021,894			(8,045,828		)	2,110,504
Noncontrolling interests	—		—		(3,271		)	—			(3,271		)
Total liabilities and stockholders’ equity	$	3,831,163	$	5,049,325	$	6,177,133		$	(10,293,153	)	$	4,764,468

15

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NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

	Condensed Consolidating Balance Sheet
	December 31, 2016
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.		Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Cash and cash equivalents	$	—	$	41,552	$	68,579		$	—		$	110,131
Trade accounts receivable, net	—		—		1,034,402			—			1,034,402
Inventories	—		364,562		456,879			—			821,441
Prepaid expenses and other current assets	13,647		34,833		211,637			(123,013		)	137,104
Total current assets	13,647		440,947		1,771,497			(123,013		)	2,103,078
Intercompany receivables, net	—		—		2,060,336			(2,060,336		)	—
Property, buildings and equipment, net	—		51,824		105,783			—			157,607
Intangible assets, net	—		3,417		389,945			—			393,362
Goodwill	—		257,623		1,473,327			—			1,730,950
Investments in affiliates	3,538,476		4,028,502		—			(7,566,978		)	—
Other assets	—		23,846		22,998			—			46,844
Total assets	$	3,552,123	$	4,806,159	$	5,823,886		$	(9,750,327	)	$	4,431,841
Accounts payable	$	—	$	381,795	$	302,926		$	—		$	684,721
Short-term debt	—		—		20,920			—			20,920
Other current liabilities	—		120,299		170,872			(123,013		)	168,158
Total current liabilities	—		502,094		494,718			(123,013		)	873,799
Intercompany payables, net	1,572,486		487,850		—			(2,060,336		)	—
Long-term debt, net	—		983,449		379,686			—			1,363,135
Other noncurrent liabilities	12,737		55,898		162,641			—			231,276
Total WESCO International, Inc. stockholders' equity	1,966,900		2,776,868		4,790,110			(7,566,978		)	1,966,900
Noncontrolling interests	—		—		(3,269		)	—			(3,269		)
Total liabilities and stockholders’ equity	$	3,552,123	$	4,806,159	$	5,823,886		$	(9,750,327	)	$	4,431,841

16

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NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

	Condensed Consolidating Statement of Income and Comprehensive Income
	Three Months Ended
	September 30, 2017
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—	$	867,973		$	1,169,377		$	(37,191	)	$	2,000,159
Cost of goods sold (excluding depreciation and
amortization)	—		697,896			954,109			(37,191		)	1,614,814
Selling, general and administrative expenses	—		140,638			139,383			—			280,021
Depreciation and amortization	—		4,475			11,599			—			16,074
Results of affiliates’ operations	53,576		42,726			—			(96,302		)	—
Interest expense (income), net	—		25,436			(8,125		)	—			17,311
Income tax (benefit) expense	—		(136		)	18,499			—			18,363
Net income	53,576		42,390			53,912			(96,302		)	53,576
Net income attributable to noncontrolling interests	—		—			(99		)	—			(99		)
Net income attributable to WESCO International, Inc.	$	53,576	$	42,390		$	54,011		$	(96,302	)	$	53,675
Other comprehensive income:
Foreign currency translation adjustments	51,148		51,148			51,148			(102,296		)	51,148
Comprehensive income attributable to WESCO International, Inc.	$	104,724	$	93,538		$	105,159		$	(198,598	)	$	104,823

	Condensed Consolidating Statement of (Loss) Income and Comprehensive (Loss) Income
	Three Months Ended
	September 30, 2016
(In thousands of dollars)	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—		$	827,648		$	1,052,915		$	(25,351	)	$	1,855,212
Cost of goods sold (excluding depreciation and
amortization)	—			663,159			852,365			(25,351		)	1,490,173
Selling, general and administrative expenses	38			128,514			126,995			—			255,547
Depreciation and amortization	—			5,114			11,823			—			16,937
Results of affiliates’ operations	100,295			71,567			—			(171,862		)	—
Interest expense (income), net	4,904			23,543			(7,655		)	—			20,792
Loss on debt redemption	123,933			—			—			—			123,933
Income tax expense (benefit)	2,441			(12,261		)	(11,329		)	—			(21,149		)
Net (loss) income	(31,021		)	91,146			80,716			(171,862		)	(31,021		)
Net income attributable to noncontrolling interests	—			—			590			—			590
Net (loss) income attributable to WESCO International, Inc.	$	(31,021	)	$	91,146		$	80,126		$	(171,862	)	$	(31,611	)
Other comprehensive loss:
Foreign currency translation adjustments	(13,993		)	(13,993		)	(13,993		)	27,986			(13,993		)
Comprehensive (loss) income attributable to WESCO International, Inc.	$	(45,014	)	$	77,153		$	66,133		$	(143,876	)	$	(45,604	)

17

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NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

	Condensed Consolidating Statement of Income and Comprehensive Income
	Nine Months Ended
	September 30, 2017
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—	$	2,490,102		$	3,289,693		$	(97,420	)	$	5,682,375
Cost of goods sold (excluding depreciation and
amortization)	—		2,002,708			2,675,608			(97,420		)	4,580,896
Selling, general and administrative expenses	—		410,624			403,651			—			814,275
Depreciation and amortization	—		13,811			33,947			—			47,758
Results of affiliates’ operations	140,915		117,907			—			(258,822		)	—
Interest expense (income), net	—		74,961			(24,114		)	—			50,847
Income tax (benefit) expense	—		(3,034		)	50,718			—			47,684
Net income	140,915		108,939			149,883			(258,822		)	140,915
Net income attributable to noncontrolling interests	—		—			(3		)	—			(3		)
Net income attributable to WESCO International, Inc.	$	140,915	$	108,939		$	149,886		$	(258,822	)	$	140,918
Other comprehensive income:
Foreign currency translation adjustments	96,097		96,097			96,097			(192,194		)	96,097
Post retirement benefit plan adjustments	252		252			252			(504		)	252
Comprehensive income attributable to WESCO International, Inc.	$	237,264	$	205,288		$	246,235		$	(451,520	)	$	237,267

18

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NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

	Condensed Consolidating Statement of Income and Comprehensive Income
	Nine Months Ended
	September 30, 2016
(In thousands of dollars)	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—		$	2,481,165		$	3,140,011		$	(78,421	)	$	5,542,755
Cost of goods sold (excluding depreciation and
amortization)	—			1,985,639			2,535,861			(78,421		)	4,443,079
Selling, general and administrative expenses	(328		)	351,663			448,021			—			799,356
Depreciation and amortization	—			15,318			34,951			—			50,269
Results of affiliates’ operations	193,266			105,401			—			(298,667		)	—
Interest expense (income), net	17,555			63,247			(21,729		)	—			59,073
Loss on debt redemption	123,933			—			—			—			123,933
Income tax (benefit) expense	(1,261		)	4,677			10,262			—			13,678
Net income	53,367			166,022			132,645			(298,667		)	53,367
Net loss attributable to noncontrolling interests	—			—			(876		)	—			(876		)
Net income attributable to WESCO International, Inc.	$	53,367		$	166,022		$	133,521		$	(298,667	)	$	54,243
Other comprehensive income (loss):
Foreign currency translation adjustments	66,512			66,512			66,512			(133,024		)	66,512
Post retirement benefit plan adjustments	(16		)	(16		)	(16		)	32			(16		)
Comprehensive income attributable to WESCO International, Inc.	$	119,863		$	232,518		$	200,017		$	(431,659	)	$	120,739

19

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NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

	Condensed Consolidating Statement of Cash Flows
	Nine Months Ended
	September 30, 2017
(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	$	(28,740	)	$	168,603		$	(58,752	)	$	—		$	81,111
Investing activities:
Capital expenditures	—			(7,435		)	(8,535		)	—			(15,970		)
Dividends received from subsidiaries	—			51,561			—			(51,561		)	—
Other	—			(174,032		)	16,711			160,811			3,490
Net cash (used in) provided by investing activities	—			(129,906		)	8,176			109,250			(12,480		)
Financing activities:
Borrowings	135,442			557,391			691,682			(173,907		)	1,210,608
Repayments	—			(587,485		)	(617,301		)	13,096			(1,191,690		)
Repurchases of common stock	(106,702		)	—			—			—			(106,702		)
Dividends paid by subsidiaries	—			—			(51,561		)	51,561			—
Other	—			(4,380		)	—			—			(4,380		)
Net cash provided by (used in) financing activities	28,740			(34,474		)	22,820			(109,250		)	(92,164		)
Effect of exchange rate changes on cash and cash equivalents	—			—			7,485			—			7,485
Net change in cash and cash equivalents	—			4,223			(20,271		)	—			(16,048		)
Cash and cash equivalents at the beginning of period	—			41,552			68,579			—			110,131
Cash and cash equivalents at the end of period	$	—		$	45,775		$	48,308		$	—		$	94,083

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WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS—(CONTINUED)

(unaudited)

	Condensed Consolidating Statement of Cash Flows
	Nine Months Ended
	September 30, 2016
(In thousands of dollars)	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net cash provided by (used in) operating activities	$	124,834		$	(274,575	)	$	366,929		$	—		$	217,188
Investing activities:
Capital expenditures	—			(9,224		)	(3,959		)	—			(13,183		)
Acquisition payments, net of cash acquired	—			(50,745		)	—			—			(50,745		)
Dividends received from subsidiaries	—			47,621			—			(47,621		)	—
Other	—			(257,768		)	(335,594		)	589,477			(3,885		)
Net cash used in investing activities	—			(270,116		)	(339,553		)	541,856			(67,813		)
Financing activities:
Borrowings	224,043			1,386,397			468,890			(257,768		)	1,821,562
Repayments	(344,804		)	(834,688		)	(500,879		)	(331,709		)	(2,012,080		)
Dividends paid by subsidiaries	—			—			(47,621		)	47,621			—
Other	(4,073		)	(3,494		)	—			—			(7,567		)
Net cash (used in) provided by financing activities	(124,834		)	548,215			(79,610		)	(541,856		)	(198,085		)
Effect of exchange rate changes on cash and cash equivalents	—			—			1,268			—			1,268
Net change in cash and cash equivalents	—			3,524			(50,966		)	—			(47,442		)
Cash and cash equivalents at the beginning of period	—			38,963			121,316			—			160,279
Cash and cash equivalents at the end of period	$	—		$	42,487		$	70,350		$	—		$	112,837

Revisions

As described in Note 2, the Condensed Consolidated Balance Sheet at December 31, 2016 has been revised to correct certain financial statement line items.

11. SUBSEQUENT EVENTS

The Company evaluated subsequent events and concluded that no subsequent events have occurred that would require recognition in the unaudited Condensed Consolidated Financial Statements or disclosure in the Notes thereto.

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WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

Item 2.    Management's Discussion and Analysis of Financial Condition and Results of Operations.

The following discussion should be read in conjunction with the information in the unaudited condensed consolidated financial statements and notes thereto included herein and WESCO International, Inc.’s Consolidated Financial Statements and Management’s Discussion and Analysis of Financial Condition and Results of Operations included in its 2016 Annual Report on Form 10-K. The matters discussed herein may contain forward-looking statements that are subject to certain risks and uncertainties that could cause actual results to differ materially from expectations. Certain of these risks are set forth in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016, as well as the Company’s other reports filed with the Securities and Exchange Commission.

Company Overview

WESCO International, Inc. (“WESCO International”), incorporated in 1993 and effectively formed in February 1994 upon acquiring a distribution business from Westinghouse Electric Corporation, is a leading North American-based distributor of products and provider of advanced supply chain management and logistics services used primarily in industrial, construction, utility, and commercial, institutional and government (“CIG”) markets. We are a leading provider of electrical, industrial, and communications maintenance, repair and operating (MRO) and original equipment manufacturer (OEM) products, construction materials, and advanced supply chain management and logistics services. Our primary product categories include general supplies, wire, cable and conduit, communications and security, electrical distribution and controls, lighting and sustainability, and automation, controls and motors.

We serve approximately 75,000 active customers globally through approximately 500 full service branches located primarily in North America, with operations in 14 additional countries and ten distribution centers located in the United States and Canada. The Company employs approximately 9,000 employees worldwide. We distribute over 1,000,000 products, grouped into six categories, from more than 25,000 suppliers utilizing a highly automated, proprietary electronic procurement and inventory replenishment system.

In addition, we offer a comprehensive portfolio of value-added capabilities, which includes supply chain management, logistics and transportation, procurement, warehousing and inventory management, as well as kitting, limited assembly of products and system installation. Our value-added capabilities, extensive geographic reach, experienced workforce and broad product and supply chain solutions have enabled us to grow our business and establish a leading position in North America.

Our financial results for the first nine months of 2017 reflect sales growth and improved business momentum in our end markets and geographies, and a challenging pricing environment. Net sales increased $139.6 million, or 2.5%, over the same period last year. Cost of goods sold as a percentage of net sales was 80.6% and 80.2% for the first nine months of 2017 and 2016, respectively. Selling, general and administrative ("SG&A") expenses as a percentage of net sales were 14.3% and 14.4% for the first nine months of 2017 and 2016, respectively. Operating profit was $239.4 million for the current nine month period, compared to $250.1 million for the first nine months of 2016. Operating profit decreased primarily due to higher SG&A payroll expenses. Net income attributable to WESCO International, Inc. for the nine months ended September 30, 2017 and 2016 was $140.9 million and $54.2 million, respectively. The increase in net income attributable to WESCO International, Inc. was primarily the result of the non-cash loss of $123.9 million related to the redemption of our 6.0% Convertible Senior Debentures due 2029 (the "2029 Debentures") in the third quarter of 2016.

Cash Flow

We generated $81.1 million of operating cash flow for the first nine months of 2017. Investing activities primarily consisted of capital expenditures of $16.0 million. Financing activities were comprised of borrowings and repayments of $589.5 million and $561.5 million, respectively, related to our revolving credit facility (the "Revolving Credit Facility"), borrowings and repayments of $490.2 million and $470.2 million, respectively, related to our accounts receivable securitization facility (the “Receivables Facility”) and repayments of $45.0 million applied to our term loan facility (the "Term Loan Facility"). Financing activities for the first nine months of 2017 also included borrowings and repayments on our various international lines of credit of approximately $130.9 million and $115.0 million, respectively. Additionally, financing activities for the first nine months of 2017 included the repurchase of $100.0 million of the Company's common stock pursuant to the share repurchase plan announced on December 17, 2014. Free cash flow for the first nine months of 2017 and 2016 was $65.1 million and $204.0 million, respectively.

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WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

The following table sets forth the components of free cash flow:

	Nine Months Ended
Free Cash Flow:	September 30, 2017			September 30, 2016
Cash flow provided by operations	$	81.1		$	217.2
Less: Capital expenditures	(16.0		)	(13.2		)
Free cash flow	$	65.1		$	204.0

Note: Free cash flow is a non-GAAP financial measure of liquidity. Capital expenditures are deducted from operating cash flow to determine free cash flow. Free cash flow is available to fund other investing and financing activities.

Financing Availability

As of September 30, 2017, we had $542.9 million in total available borrowing capacity under our Revolving Credit Facility, which matures in September 2020, and $150.0 million in available borrowing capacity under our Receivables Facility, which matures in September 2018.

Critical Accounting Policies and Estimates

During the three months ended March 31, 2017, the Company adopted ASU 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. See Note 2 of our Notes to the Condensed Consolidated Financial Statements for information regarding our critical accounting policies.

Results of Operations

Third Quarter of 2017 versus Third Quarter of 2016

The following table sets forth the percentage relationship to net sales of certain items in our Condensed Consolidated Statements of Income (Loss) and Comprehensive Income (Loss) for the periods presented:

	Three Months Ended
	September 30,
	2017		2016
Net sales	100.0	%	100.0	%
Cost of goods sold (excluding depreciation and amortization)	80.7		80.3
Selling, general and administrative expenses	14.0		13.8
Depreciation and amortization	0.8		0.9
Income from operations	4.5		5.0
Interest expense, net	0.9		1.1
Loss on debt redemption	—		6.7
Income (loss) before income taxes	3.6		(2.8	)
Provision for income taxes	0.9		(1.1	)
Net income (loss) attributable to WESCO International, Inc.	2.7	%	(1.7	)%

Net sales were $2.0 billion for the third quarter of 2017, compared to $1.86 billion for the third quarter of 2016, an increase of 7.8%. Organic sales for the third quarter of 2017 grew by 8.6% as foreign exchange rates positively impacted net sales by 0.8% and were more than offset by a 1.6% impact from the number of workdays.

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WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

The following table sets forth organic sales growth for the period presented:

	Three Months Ended
Organic Sales Growth:	September 30, 2017
Change in net sales	7.8	%
Impact from acquisitions	—	%
Impact from foreign exchange rates	0.8	%
Impact from number of workdays	(1.6	)%
Organic sales growth	8.6	%

Note: Organic sales growth is a non-GAAP financial measure of sales performance. Organic sales growth is calculated by deducting the percentage impact from acquisitions in the first year of ownership, foreign exchange rates and number of workdays from the overall percentage change in consolidated net sales.

Cost of goods sold for the third quarter of 2017 was $1.61 billion, compared to $1.49 billion for the third quarter of 2016. As a percentage of net sales, cost of goods sold was 80.7% and 80.3% for the three months ended September 30, 2017 and 2016, respectively. The increase in cost of goods sold as a percentage of net sales was primarily due to business mix and a challenging pricing environment.

SG&A expenses in the third quarter of 2017 totaled $280.0 million versus $255.5 million in last year's comparable quarter. As a percentage of net sales, SG&A expenses were 14.0% and 13.8%, respectively. SG&A expenses in the current quarter were $24.5 million more than the prior quarter primarily due to higher SG&A payroll expenses.

SG&A payroll expenses for the third quarter of 2017 of $197.9 million increased by $17.0 million compared to the same quarter in 2016 primarily due to higher variable compensation expense and temporary labor costs.

Depreciation and amortization for the third quarter of 2017 and 2016 was $16.1 million and $16.9 million, respectively.

Interest expense totaled $17.3 million for the third quarter of 2017 compared to $20.8 million in last year's comparable quarter. The decrease of 16.7% was primarily due to a reduction in higher-priced debt. Non-cash interest expense for the third quarter of 2017 and 2016, which includes amortization of debt discounts and deferred financing fees, and interest related to uncertain tax positions, was $0.8 million and $1.9 million, respectively.

Loss on debt redemption of $123.9 million for the third quarter of 2016 was due to the early redemption of the 2029 Debentures on September 15, 2016.

Income tax expense totaled $18.4 million for the third quarter of 2017 compared to a benefit of $21.1 million in last year's comparable quarter and the effective tax rate was 25.5% and 40.5%, respectively. The income tax benefit in the third quarter of 2016 resulted from the redemption of the 2029 Debentures. As adjusted, the effective tax rate for the third quarter of 2016 was 28.0%. The lower effective tax rate in the current quarter as compared to the adjusted effective tax rate for the prior year's comparable quarter is primarily the result of favorable discrete items and the mix of income earned in jurisdictions with lower tax rates.

The following table sets forth the adjusted provision for income taxes:

	Three Months Ended
Adjusted Tax Provision:	September 30, 2017		September 30, 2016
Provision for income taxes	$	18.4	$	(21.1	)
Income tax benefit from loss on debt redemption	—		41.2
Adjusted provision for income taxes	$	18.4	$	20.1

Note: The adjusted provision for income taxes excludes the benefit from the loss on debt redemption. The Company believes that this non-GAAP financial measure is useful to investors' overall understanding of the Company's current financial performance and provides a consistent measure for assessing the current and historical financial results.

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WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

Net income for the third quarter of 2017 was $53.6 million, compared to a net loss of $31.0 million for the third quarter of 2016, which was primarily due to the loss recognized as a result of the early redemption of the 2029 Debentures. Adjusted net income was $51.7 million for the three months ended September 30, 2016.

Net loss of $0.1 million was attributable to noncontrolling interests for the third quarter of 2017, as compared to net income of $0.6 million for the third quarter of 2016. The change in net income (loss) attributable to noncontrolling interests was primarily due to the effect of foreign currency.

Net income and diluted earnings per share attributable to WESCO International, Inc. were $53.7 million and $1.12 per share, respectively, for the third quarter of 2017, compared with a net loss and diluted loss per share of $31.6 million and $0.73 per share, respectively, for the third quarter of 2016. Adjusted net income and adjusted diluted earnings per share attributable to WESCO International, Inc. were $51.1 million and $1.05 per share, respectively, for the three months ended September 30, 2016.

The following table sets forth adjusted net income attributable to WESCO International, Inc. and adjusted earnings per diluted share:

	Three Months Ended
Adjusted Income Before Income Taxes:	September 30, 2017			September 30, 2016
Income (loss) before income taxes	$	72.0		$	(52.1	)
Loss on debt redemption	—			123.9
Adjusted income before income taxes	$	72.0		$	71.8
Adjusted Net Income Attributable to WESCO International, Inc.:
Adjusted income before income taxes	$	72.0		$	71.8
Adjusted provision for income taxes	18.4			20.1
Adjusted net income	53.6			51.7
Net (loss) income attributable to noncontrolling interests	(0.1		)	0.6
Adjusted net income attributable to WESCO
International, Inc.	$	53.7		$	51.1
Adjusted Earnings Per Diluted Share:
Diluted shares	47.8			48.7
Adjusted earnings per diluted share	$	1.12		$	1.05

Note: Adjusted net income attributable to WESCO International, Inc. is defined as income (loss) before income taxes plus the loss on debt redemption, less the provision for income taxes excluding the benefit of such loss. Adjusted earnings per diluted share is computed by dividing adjusted net income attributable to WESCO International, Inc. by the weighted-average common shares outstanding and common share equivalents. The Company believes that these non-GAAP financial measures are useful to investors' overall understanding of the Company's current financial performance and provides a consistent measure for assessing the current and historical financial results.

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WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

Nine Months Ended September 30,2017 versus Nine Months Ended September 30,2016

The following table sets forth the percentage relationship to net sales of certain items in our Condensed Consolidated Statements of Income and Comprehensive Income for the periods presented:

	Nine Months Ended
	September 30,
	2017		2016
Net sales	100.0	%	100.0	%
Cost of goods sold (excluding depreciation and amortization)	80.6		80.2
Selling, general and administrative expenses	14.3		14.4
Depreciation and amortization	0.9		0.9
Income from operations	4.2		4.5
Interest expense, net	0.9		1.1
Loss on debt redemption	—		2.2
Income before income taxes	3.3		1.2
Provision for income taxes	0.8		0.2
Net income attributable to WESCO International, Inc.	2.5	%	1.0	%

Net sales were $5.68 billion for the first nine months of 2017, compared to $5.54 billion for the first nine months of 2016, an increase of 2.5%. Organic sales for the first nine months of 2017 grew by 2.7% as acquisitions had a positive impact on net sales of 0.3% and were more than offset by a 0.5% impact from the number of workdays.

The following table sets forth organic sales growth for the period presented:

	Nine Months Ended
Organic Sales Growth:	September 30, 2017
Change in net sales	2.5	%
Impact from acquisitions	0.3	%
Impact from foreign exchange rates	—	%
Impact from number of workdays	(0.5	)%
Organic sales growth	2.7	%

Note: Organic sales growth is a non-GAAP financial measure of sales performance. Organic sales growth is calculated by deducting the percentage impact from acquisitions in the first year of ownership, foreign exchange rates and number of workdays from the overall percentage change in consolidated net sales.

Cost of goods sold for the first nine months of 2017 was $4.58 billion, compared to $4.44 billion for the first nine months of 2016. As a percentage of net sales, cost of goods sold was 80.6% and 80.2% for the nine months ended September 30, 2017 and 2016, respectively. The increase in cost of goods sold as a percentage of net sales was primarily due to business mix and a challenging pricing environment.

SG&A expenses in the first nine months of 2017 totaled $814.3 million versus $799.4 million in last year's comparable period. As a percentage of net sales, SG&A expenses were 14.3% in the first nine months of 2017 compared to 14.4% in the first nine months of 2016. SG&A expenses increased due to higher SG&A payroll expenses.

SG&A payroll expenses for the first nine months of 2017 of $573.2 million increased by $12.4 million compared to the same period in 2016 primarily due to higher variable compensation expense and temporary labor costs.

Depreciation and amortization for the first nine months of 2017 and 2016 was $47.8 million and $50.3 million, respectively.

Interest expense totaled $50.8 million for the first nine months of 2017 compared to $59.1 million for the first nine months of 2016. The decrease of 14.0% was primarily due to a reduction in higher-priced debt. Non-cash interest expense for the first nine months of 2017 and 2016, which includes amortization of debt discounts and deferred financing fees, and interest related to uncertain tax positions, was $3.0 million and $6.1 million, respectively.

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WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

Loss on debt redemption of $123.9 million for the nine months ended September 30, 2016 was due to the early redemption of the 2029 Debentures on September 15, 2016.

Income tax expense totaled $47.7 million for the first nine months of 2017 compared to $13.7 million in last year's comparable period and the effective tax rate was 25.3% and 20.4%, respectively. As adjusted, the effective tax rate for the first nine months of 2016 was 28.8%. The current year's effective tax rate is lower than the prior year's adjusted effective tax rate primarily due to favorable discrete items, including a benefit from the exercise and vesting of stock-based awards, as well as the mix of income earned in jurisdictions with lower tax rates.

The following table sets forth the adjusted provision for income taxes:

	Nine Months Ended
Adjusted Tax Provision:	September 30, 2017		September 30, 2016
Provision for income taxes	$	47.7	$	13.7
Income tax benefit from loss on debt redemption	—		41.2
Adjusted provision for income taxes	$	47.7	$	54.9

Note: The adjusted provision for income taxes excludes the benefit from the loss on debt redemption. The Company believes that this non-GAAP financial measure is useful to investors' overall understanding of the Company's current financial performance and provides a consistent measure for assessing the current and historical financial results.

For the first nine months of 2017, net income increased by $87.5 million to $140.9 million, compared to net income of $53.4 million for the first nine months of 2016.The increase in net income was primarily due to the loss recognized in the prior year as a result of the early redemption of the 2029 Debentures. Adjusted net income for the nine months ended September 30, 2016 was $136.0 million.

Net loss of less than $0.1 million and $0.9 million was attributable to noncontrolling interests for the first nine months of 2017 and 2016, respectively. The change in net loss attributable to noncontrolling interests was primarily due to the effect of foreign currency.

Net income and diluted earnings per share attributable to WESCO International, Inc. were $140.9 million and $2.90 per share, respectively, for the first nine months of 2017, compared with net income and diluted earnings per share of $54.2 million and $1.13 per share, respectively, for the first nine months of 2016. Adjusted net income and diluted earnings per share attributable to WESCO International, Inc. were $136.9 million and $2.85 per share, respectively, for the nine months ended September 30, 2016.

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WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

The following table sets forth adjusted net income attributable to WESCO International, Inc. and adjusted earnings per diluted share:

	Nine Months Ended
Adjusted Income Before Income Taxes:	September 30, 2017		September 30, 2016
Income before income taxes	$	188.6	$	67.0
Loss on debt redemption	—		123.9
Adjusted income before income taxes	$	188.6	$	190.9
Adjusted Net Income Attributable to WESCO International, Inc.:
Adjusted income before income taxes	$	188.6	$	190.9
Adjusted provision for income taxes	47.7		54.9
Adjusted net income	140.9		136.0
Net loss attributable to noncontrolling interests	—		(0.9		)
Adjusted net income attributable to WESCO
International, Inc.	$	140.9	$	136.9
Adjusted Earnings Per Diluted Share:
Diluted shares	48.6		48.0
Adjusted earnings per diluted share	$	2.90	$	2.85

Note: Adjusted net income attributable to WESCO International, Inc. is defined as income (loss) before income taxes plus the loss on debt redemption, less the provision for income taxes excluding the benefit of such loss. Adjusted earnings per diluted share is computed by dividing adjusted net income attributable to WESCO International, Inc. by the weighted-average common shares outstanding and common share equivalents. The Company believes that these non-GAAP financial measures are useful to investors' overall understanding of the Company's current financial performance and provides a consistent measure for assessing the current and historical financial results.

Liquidity and Capital Resources

Total assets were $4.76 billion at September 30, 2017 and $4.43 billion at December 31, 2016. Total liabilities were $2.66 billion at September 30, 2017 and $2.47 billion at December 31, 2016. Stockholders’ equity increased $143.6 million to $2.11 billion at September 30, 2017, primarily due to net income of $140.9 million and foreign currency translation adjustments of $96.1 million. These increases were partially offset by the repurchase of $100.0 million of the Company's common stock pursuant to the share repurchase program.

Our liquidity needs generally arise from fluctuations in our working capital requirements, capital expenditures, acquisitions and debt service obligations. As of September 30, 2017, we had $542.9 million in available borrowing capacity under our Revolving Credit Facility and $150.0 million in available borrowing capacity under our Receivables Facility, which combined with available cash of $49.5 million, provided liquidity of $742.4 million. Cash included in our determination of liquidity represents cash in deposit and interest bearing investment accounts. We believe cash provided by operations and financing activities will be adequate to cover our current operational and business needs. In addition, the Company regularly reviews its mix of fixed versus variable rate debt, and the Company may, from time to time, issue or retire borrowings and/or refinance existing debt in an effort to mitigate the impact of interest rate fluctuations and to maintain a cost-effective capital structure consistent with its anticipated capital requirements. At September 30, 2017, approximately 60% of the Company's debt portfolio was comprised of fixed rate debt.

We monitor the depository institutions that hold our cash and cash equivalents on a regular basis, and we believe that we have placed our deposits with creditworthy financial institutions. We also communicate on a regular basis with our lenders regarding our financial and working capital performance, liquidity position and financial leverage. Our financial leverage ratio was 3.7 and 3.5 as of September 30, 2017 and December 31, 2016, respectively. In addition, we are in compliance with all covenants and restrictions contained in our debt agreements as of September 30, 2017.

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WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

The following table sets forth the Company's financial leverage ratio as of September 30, 2017 and December 31, 2016:

	Twelve months ended
Financial Leverage:	September 30, 2017		December 31, 2016
	(In millions of dollars, except ratio)
Income from operations	$	321.5	$	332.0
Depreciation and amortization	64.3		66.9
EBITDA	$	385.8	$	398.9
	September 30, 2017		December 31, 2016
Current debt and short-term borrowings	$	40.9	$	22.1
Long-term debt	1,368.3		1,363.1
Debt discount and deferred financing fees(1)	14.3		17.3
Total debt	$	1,423.5	$	1,402.5
Financial leverage ratio based on total debt	3.7		3.5

⁽¹⁾  Long-term debt is presented in the condensed consolidated balance sheets net of deferred financing fees and debt discount.

Note: Financial leverage is a non-GAAP measure of the use of debt. Financial leverage ratio is calculated by dividing total debt, including debt discount and deferred financing fees, by EBITDA. EBITDA, which is also a non-GAAP financial measure, is defined as the trailing twelve months earnings before interest, taxes, depreciation and amortization.

At September 30, 2017, we had cash and cash equivalents totaling $94.1 million, of which $63.9 million was held by foreign subsidiaries. The cash held by some of our foreign subsidiaries could be subject to additional U.S. income taxes if repatriated. We believe that we are able to maintain a sufficient level of liquidity for our domestic operations and commitments without repatriation of the cash held by these foreign subsidiaries.

We did not note any triggering events or substantive changes during the first nine months of 2017 that would require an interim evaluation of impairment of goodwill or indefinite-lived intangible assets. We will perform our annual impairment testing of goodwill and indefinite-lived intangible assets during the fourth quarter. To test for impairment, we estimate the fair value of our reporting units, which requires judgment and involves the use of significant estimates and assumptions. The determination of fair value could be affected by the current economic environment and conditions in the markets in which we operate and those where our customers are based.

Over the next several quarters, we plan to closely manage working capital, and it is expected that excess cash will be directed primarily at acquisitions, debt reduction and share repurchases. We remain focused on maintaining ample liquidity and credit availability. We believe our balance sheet and ability to generate ample cash flow provides us with a durable business model and should allow us to fund expansion needs and growth initiatives.

Cash Flow

Operating Activities. Net cash provided by operating activities for the first nine months of 2017 totaled $81.1 million, compared with $217.2 million of cash generated for the first nine months of 2016. Net cash provided by operating activities included net income of $140.9 million and adjustments to net income totaling $68.8 million. Other sources of cash in 2017 included an increase in accounts payable of $138.3 million, a decrease in other accounts receivable of $4.4 million and an increase in accrued payroll and benefit costs of $2.4 million. Primary uses of cash in 2017 included: an increase in trade accounts receivable of $174.7 million resulting from higher sales in the latter part of the first nine months of 2017; an increase in inventories of $86.7 million; an increase in prepaid expenses and other assets of $8.5 million; and, a decrease in other current and noncurrent liabilities of $3.8 million.

Net cash provided by operating activities for the first nine months of 2016 totaled $217.2 million, which included net income of $53.4 million and adjustments to net income totaling $163.6 million. Other sources of cash in 2016 included: an increase in other current and noncurrent liabilities of $37.0 million; and, a decrease in other accounts receivable of $15.5 million due to lower supplier volume rebate accruals. Primary uses of cash in 2016 included: a decrease in accounts payable of $30.3 million; an increase in prepaid expenses and other assets of $8.6 million; an increase in inventories of $7.7 million; an increase in trade receivables of $3.1 million; and, a decrease in accrued payroll and benefit costs of $2.6 million.

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WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

Investing Activities. Net cash used in investing activities for the first nine months of 2017 was $12.5 million, compared with $67.8 million of net cash used during the first nine months of 2016. Capital expenditures were $16.0 million for the nine month period ended September 30, 2017, compared to $13.2 million for the nine month period ended September 30, 2016. The first nine months of 2016 also included net acquisition payments of $50.7 million.

Financing Activities. Net cash used in financing activities for the first nine months of 2017 was $92.2 million, compared to $198.1 million used in the first nine months of 2016. During the first nine months of 2017, financing activities consisted of borrowings and repayments of $589.5 million and $561.5 million, respectively, related to our Revolving Credit Facility, borrowings and repayments of $490.2 million and $470.2 million, respectively, related to our Receivables Facility and repayments of $45.0 million applied to our Term Loan Facility. Financing activities for the first nine months of 2017 also included borrowings and repayments on our various international lines of credit of approximately $130.9 million and $115.0 million, respectively. Additionally, financing activities for the nine months ended September 30, 2017 included the repurchase of $106.7 million of the Company's common stock, of which $100.0 million was pursuant to the share repurchase plan announced on December 17, 2014.

During the first nine months of 2016, financing activities consisted of borrowings and repayments of $789.4 million and $864.4 million, respectively, related to our Revolving Credit Facility, borrowings and repayments of $592.3 million and $691.3 million, respectively, related to our Receivables Facility, proceeds of $350.0 million from the issuance of 5.375% Senior Notes due 2024, a payment of $344.8 million to redeem our 2029 Debentures and repayments of $15.0 million applied to our Term Loan Facility. Financing activities in 2016 also included borrowings and repayments on our various international lines of credit of approximately $89.8 million and $96.5 million, respectively.

Contractual Cash Obligations and Other Commercial Commitments

There were no material changes in our contractual obligations and other commercial commitments that would require an update to the disclosure provided in our 2016 Annual Report on Form 10-K. Management believes that cash generated from operations, together with amounts available under our Revolving Credit Facility and the Receivables Facility, will be sufficient to meet our working capital, capital expenditures and other cash requirements for the foreseeable future. However, there can be no assurances that this will continue to be the case.

Inflation

The rate of inflation, as measured by changes in the producer price index, affects different commodities, the cost of products purchased and ultimately the pricing of our different products and product classes to our customers. For the nine months ended September 30, 2017, pricing related to inflation did not have a measurable impact on our sales. Historically, price changes from suppliers have been consistent with inflation and have not had a material impact on the results of operations.

Seasonality

Our operating results are not significantly affected by seasonal factors. Sales during the first quarter are affected by a reduced level of activity. Sales during the second, third and fourth quarters are generally 6 - 8% higher than the first quarter. Sales typically increase beginning in March, with slight fluctuations per month through October. During periods of economic expansion or contraction, our sales by quarter have varied significantly from this pattern.

Impact of Recently Issued Accounting Standards

See Note 2 of our Notes to Condensed Consolidated Financial Statements for information regarding the effect of new accounting pronouncements.

30

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

Forward-Looking Statements

From time to time in this report and in other written reports and oral statements, references are made to expectations regarding our future performance. When used in this context, the words “anticipates,” “plans,” “believes,” “estimates,” “intends,” “expects,” “projects,” “will” and similar expressions may identify forward-looking statements, although not all forward-looking statements contain such words. Such statements including, but not limited to, our statements regarding business strategy, growth strategy, competitive strengths, productivity and profitability enhancement, competition, new product and service introductions and liquidity and capital resources are based on management’s beliefs, as well as on assumptions made by and information currently available to, management, and involve various risks and uncertainties, some of which are beyond our control. Our actual results could differ materially from those expressed in any forward-looking statement made by us or on our behalf. In light of these risks and uncertainties, there can be no assurance that the forward-looking information will in fact prove to be accurate. Certain of these risks are set forth in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016, as well as the Company’s other reports filed with the Securities and Exchange Commission. We have undertaken no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

Item 3.    Quantitative and Qualitative Disclosures about Market Risks.

There have not been any material changes to our exposures to market risk during the quarter ended September 30, 2017 that would require an update to the relevant disclosures provided in our 2016 Annual Report on Form 10-K.

Item 4.    Controls and Procedures.

Under the supervision and with the participation of our management, including our principal executive officer and principal financial officer, we conducted an evaluation of our disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)). Based on this evaluation, our principal executive officer and our principal financial officer concluded that our disclosure controls and procedures and internal control over financial reporting were effective as of the end of the period covered by this report.

During the third quarter of 2017, there were no changes in our internal control over financial reporting that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

31

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

PART II—OTHER INFORMATION

Item 1. Legal Proceedings.

From time to time, a number of lawsuits and claims have been or may be asserted against us relating to the conduct of our business, including routine litigation relating to commercial and employment matters. The outcome of any litigation cannot be predicted with certainty, and some lawsuits may be determined adversely to us. However, management does not believe that the ultimate outcome of any such pending matters is likely to have a material adverse effect on our financial condition or liquidity, although the resolution in any fiscal period of one or more of these matters may have a material adverse effect on our results of operations for that period.

See the information set forth in Note 8, Commitments and Contingencies in the Notes to Condensed Consolidated Financial Statements under Part 1, Item 1 of this Form 10-Q, which is incorporated by reference in response to this Item.

Item 1A. Risk Factors.

There have been no material changes to the risk factors previously disclosed in Item 1A. to Part 1 of WESCO’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016.

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds.

The following table sets forth all issuer purchases of common stock during the three months ended September 30, 2017, including those made pursuant to publicly announced plans or programs:

Period	Total Number of Shares Purchased (2)	Average Price Paid Per Share		Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs (1)	Approximate Dollar Value of Shares That May Yet be Purchased Under the Plans or Program (1)
					(In Millions)
July 1 – July 31, 2017	256	$	56.65	—	$	100.0
August 1 – August 31, 2017	974,282	$	51.32	974,246	$	50.0
September 1 – September 30, 2017	371	$	56.25	—	$	50.0
Total	974,909	$	51.33	974,246

⁽¹⁾  On December 17, 2014, WESCO announced that its Board of Directors approved, on December 11, 2014, the repurchase of up to $300 million of the Company's common stock through December 31, 2017.

⁽²⁾  There were 663 shares purchased in the period that were not part of the publicly announced share repurchase program. These shares were surrendered by stock-based compensation plan participants to satisfy tax withholding obligations arising from the exercise of stock-settled stock appreciation rights.

32

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

Item 6.Exhibits.

(a)Exhibits

(31)    Rule 13a-14(a)/15d-14(a) Certifications

(1) Certification of Chief Executive Officer pursuant to Rules 13a-14(a) promulgated under the Exchange Act.

(2) Certification of Chief Financial Officer pursuant to Rules 13a-14(a) promulgated under the Exchange Act.

(32)    Section 1350 Certifications

(1) Certification of Chief Executive Officer pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

(2) Certification of Chief Financial Officer pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

101.INS    XBRL Instance Document.

101.SCH    XBRL Taxonomy Extension Schema Document.

101.CAL    XBRL Taxonomy Extension Calculation Linkbase Document.

101.DEF    XBRL Taxonomy Extension Definition Linkbase Document.

101.LAB    XBRL Taxonomy Extension Label Linkbase Document.

101.PRE    XBRL Taxonomy Extension Presentation Linkbase Document.

33

WESCO INTERNATIONAL, INC. AND SUBSIDIARIES

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

WESCO International, Inc.

(Registrant)

November 3, 2017	By:	/s/ David S. Schulz
(Date)		David S. Schulz
		Senior Vice President and Chief Financial Officer

34

EX-31.1

Exhibit 31.1

CERTIFICATION

     I, John J. Engel, certify that:

     1.      I have reviewed this quarterly report on Form 10-Q of WESCO International, Inc.;

     2.     Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

     3.     Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

     4.      The registrant's other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

    (a)      Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

    (b)      Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

    (c)      Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

    (d)      Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

     5.      The registrant's other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

    (a)      All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date:	November 3, 2017	By:	/s/ John J. Engel
			John J. Engel
			Chairman, President and Chief Executive Officer

EX-31.2

Exhibit 31.2

CERTIFICATION

     I, David S. Schulz, certify that:

     1.      I have reviewed this quarterly report on Form 10-Q of WESCO International, Inc.;

     2.     Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

     3.     Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

     4.      The registrant's other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

    (a)      Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

    (b)      Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

    (c)      Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

    (d)      Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

     5.      The registrant's other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

    (a)      All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

    (b)      Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date:	November 3, 2017	By:	/s/ David S. Schulz
			David S. Schulz
			Senior Vice President and Chief Financial Officer

EX-32.1

Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of WESCO International, Inc. (the “Company”) on Form 10-Q for the period ended September 30, 2017 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), the undersigned, in the capacity and on the date indicated below, hereby certifies pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to his knowledge:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operation of the Company.

November 3, 2017	By:	/s/ John J. Engel
		John J. Engel
		Chairman, President and Chief Executive Officer

EX-32.2

Exhibit 32.2

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of WESCO International, Inc. (the “Company”) on Form 10-Q for the period ended September 30, 2017 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), the undersigned, in the capacity and on the date indicated below, hereby certifies pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to his knowledge:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operation of the Company.

November 3, 2017	By:	/s/ David S. Schulz
		David S. Schulz
		Senior Vice President and Chief Financial Officer

XML

DOCUMENT AND ENTITY INFORMATION Document - shares	9 Months Ended
	Sep. 30, 2017	Nov. 02, 2017
Entity [Abstract]
Entity Registrant Name	WESCO INTERNATIONAL INC.
Entity Central Index Key	0000929008
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		47,002,338

XML

CONSOLIDATED BALANCE SHEETS $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Depreciation, Depletion and Amortization, Nonproduction	$ 16,074	$ 47,758
Other Accrued Liabilities, Current	87,143	87,143
Current Assets:
Cash and cash equivalents	94,083	94,083	$ 110,131
Allowance for Doubtful Accounts Receivable, Current	24,240	24,240	22,007
Trade accounts receivable, net of allowance for doubtful accounts of $23,069 and $19,309 in 2014 and 2013, respectively	1,236,612	1,236,612	1,034,402
Accounts and Other Receivables, Net, Current	82,588	82,588	85,019
Inventories, net	925,049	925,049	821,441
Prepaid expenses and other current assets	71,795	71,795
Total current assets	2,410,127	2,410,127	2,103,078
Property, buildings and equipment, net of accumulated depreciation of $229,041 and $213,758 in 2014 and 2013, respectively	157,591	157,591	157,607
Intangible assets, net	378,153	378,153	393,362
Goodwill	1,776,918	1,776,918	1,730,950
Other assets	41,679	41,679	46,844
Total assets	4,764,468	4,764,468	4,431,841
Current Liabilities:
Accounts payable	838,427	838,427	684,721
Accrued payroll and benefit costs	50,848	50,848	49,250
Short-term debt	39,712	39,712	20,920
Current portion of long-term debt	1,213	1,213	1,218
Total current liabilities	1,043,493	1,043,493	873,799
Long-term Debt, Excluding Current Maturities	1,368,301	1,368,301	1,363,135
Other noncurrent liabilities	65,811	65,811	63,031
Deferred Tax Liabilities, Net, Noncurrent	179,630	179,630
Total liabilities	2,657,235	2,657,235	2,468,210
Commitments and Contingencies
Bank Overdrafts	26,150	26,150	29,384
Stockholders' Equity:
Preferred stock, $.01 par value; 20,000,000 shares authorized, no shares issued or outstanding	0	0	0
Additional capital	995,670	995,670	986,020
Retained earnings	2,056,961	2,056,961
Treasury stock, at cost; 18,247,467 and 18,179,275 shares in 2014 and 2013, respectively	(647,138)	(647,138)	(542,537)
Accumulated other comprehensive income	(295,622)	(295,622)
Total WESCO International stockholders' equity	2,107,233	2,107,233	1,963,631
Noncontrolling interest	(3,271)	(3,271)	(3,269)
Total stockholders' equity	2,110,504	2,110,504	1,966,900
Total liabilities and stockholders' equity	4,764,468	4,764,468	4,431,841
Common Stock [Member]
Stockholders' Equity:
Common stock	590	590	588
Common Class B [Member]
Stockholders' Equity:
Common stock	$ 43	$ 43	$ 43

XML

CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Allowance for doubtful accounts	$ 24,240,000	$ 22,007,000
Accumulated depreciation	274,643,000	259,126,000
Finite-Lived Intangible Assets, Accumulated Amortization	214,225	178,813
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	$ 14,302,000	$ 17,278,000
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)	16,375,816	14,545,715
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)	59,036,037	58,817,781
Common stock, shares outstanding (in shares)	46,999,652	48,611,497
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

XML

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Net sales	$ 2,000,159	$ 1,855,212	$ 5,682,375	$ 5,542,755
Cost of goods sold	1,614,814	1,490,173	4,580,896	4,443,079
Selling, general and administrative expense	280,021	255,547	814,275	799,356
Depreciation and amortization	16,074	16,937	47,758	50,269
Income from operations	89,250	92,555	239,446	250,051
Interest expense, net	17,311	20,792	50,847	59,073
Gain (Loss) on Extinguishment of Debt	0	123,933	0	123,933
Income before income taxes	71,939	(52,170)	188,599	67,045
Provision for income taxes	18,363	(21,149)	47,684	13,678
Net income	53,576	(31,021)	140,915	53,367
Net (loss) income attributable to noncontrolling interest	(99)	590	(3)	(876)
Net income attributable to WESCO International, Inc.	53,675	(31,611)	140,918	54,243
Comprehensive Income:
Foreign currency translation adjustment	51,148	(13,993)	96,097	66,512
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	0	0	252	(16)
Comprehensive income attributable to WESCO International, Inc.	$ 104,823	$ (45,604)	$ 237,267	$ 120,739
Earnings per share attributable to WESCO International, Inc.
Basic (in dollars per share)	$ 1.13	$ (0.73)	$ 2.93	$ 1.27
Diluted (in dollars per share)	$ 1.12	$ (0.73)	$ 2.90	$ 1.13

XML

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating Activities:
Net income	$ 140,915	$ 53,367
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	47,758	50,269
Deferred income taxes	8,433	(21,842)
Gain (Loss) on Extinguishment of Debt	0	123,933
Other operating activities, net	12,617	11,228
Changes in assets and liabilities
Increase (Decrease) in Accounts Receivable	174,667	3,075
Increase (Decrease) in Accounts and Other Receivables	(4,421)	(15,524)
Inventories, net	(86,736)	(7,651)
Prepaid expenses and other current assets	(8,515)	(8,625)
Accounts payable	138,348	(30,289)
Accrued payroll and benefit costs	2,383	(2,648)
Other current and noncurrent liabilities	(3,846)	36,997
Net cash provided by operating activities	81,111	217,188
Investing Activities:
Capital expenditures	(15,970)	(13,183)
Acquisition payments, net of cash acquired	0	(50,745)
Other investing activities	3,490	(3,885)
Net cash used in investing activities	(12,480)	(67,813)
Financing Activities:
Proceeds from issuance of short-term debt	130,890	89,847
Repayments of short-term debt	(114,972)	(96,535)
Proceeds from issuance of long-term debt	1,079,718	1,731,715
Repayments of Long-term Debt	(1,076,718)	(1,915,545)
Other financing activities, net	(4,380)	(3,494)
Net cash used in financing activities	(92,164)	(198,085)
Payments for Repurchase of Common Stock	(106,702)	(4,073)
Effect of exchange rate on cash and cash equivalents	7,485	1,268
Net change in cash and cash equivalents	(16,048)	(47,442)
Cash and cash equivalents at the beginning of period	110,131	160,279
Cash and cash equivalents at the end of period	$ 94,083	$ 112,837

XML

ORGANIZATION

9 Months Ended

Sep. 30, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

ORGANIZATION

1. ORGANIZATION

WESCO International, Inc. ("WESCO International") 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 manufacturer (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 approximately 75,000 active customers globally, through approximately 500 full service branches and ten distribution centers located primarily in the United States, Canada and Mexico, with operations in 14 additional countries.

XML

ACCOUNTING POLICIES

9 Months Ended

Sep. 30, 2017

Accounting Policies [Abstract]

ACCOUNTING POLICIES

2. 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 2016 Annual Report on Form 10-K as filed with the SEC on February 22, 2017. The Condensed Consolidated Balance Sheet at December 31, 2016 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, 2017, the unaudited Condensed Consolidated Statements of Income and Comprehensive Income for the three and nine months ended September 30, 2017 and 2016, respectively, and the unaudited Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2017 and 2016, 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.

Revision of Prior Period Financial Statements

In the third quarter of 2017, management determined that the Company's income taxes receivable and payable and other tax account balances were overstated as of December 31, 2016 by a cumulative net amount of $46.4 million, which related to multiple prior periods. The Company also identified a $10.2 million understatement related to deferred income taxes and goodwill. In accordance with Staff Accounting Bulletin (“SAB”) No. 99, Materiality, and SAB No. 108, Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements, management concluded that these misstatements are not material to the Company's previously issued annual and interim financial statements. Correcting the effected financial statement line items in the quarterly period ended September 30, 2017 would materially misstate the condensed consolidated financial information presented herein. Accordingly, the Condensed Consolidated Balance Sheet at December 31, 2016 in this Quarterly Report on Form 10-Q has been revised. There was an immaterial effect on the Condensed Consolidated Statements of Income and Comprehensive Income for the three and nine months ended September 30, 2016, and no effect on the Condensed Consolidated Statements of Cash Flows for the respective periods presented herein. Periods not presented herein will be revised, as applicable, in future filings.

The following table presents the effects on the financial statement line items that were revised:

	December 31, 2016
	As Reported			Adjustment			As Revised
	(In thousands)
Prepaid expenses and other current assets	$	121,464		$	(69,379	)	$	52,085
Total current assets	2,172,457			(69,379		)	2,103,078
Goodwill	1,720,714			10,236			1,730,950
Total assets	4,490,984			(59,143		)	4,431,841
Other current liabilities	111,304			(22,998		)	88,306
Total current liabilities	896,797			(22,998		)	873,799
Deferred income taxes	158,009			10,236			168,245
Total liabilities	2,480,972			(12,762		)	2,468,210
Retained earnings	1,956,532			(41,775		)	1,914,757
Accumulated other comprehensive loss	(387,365		)	(4,606		)	(391,971		)
Total stockholders' equity	2,010,012			(46,381		)	1,963,631
Total liabilities and stockholders' equity	4,490,984			(59,143		)	4,431,841

Recently Adopted Accounting Pronouncements

In March 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, which simplifies several aspects of accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments in this ASU affect all entities that issue share-based payment awards to their employees. The Company adopted this ASU in the first quarter of 2017. The amendment related to the recognition of excess tax benefits and deficiencies was applied prospectively and, as disclosed in Note 9, lowered the Company's effective tax rate for the nine months ended September 30, 2017. The amendment related to the presentation of excess tax benefits on the statement of cash flows was also applied prospectively, and did not have a material impact on WESCO's cash flows. The other amendments, which were adopted by the Company according to the respective transition requirements, had no impact on the consolidated financial statements and notes thereto.

In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory. The purpose of ASU 2016-16 is to simplify the income tax accounting of an intra-entity transfer of an asset other than inventory and to record its effect when the transfer occurs. The Company early adopted this ASU on a modified retrospective basis in the first quarter of 2017. The adoption of this ASU did not have a material impact on WESCO's financial position and it had no impact on its results of operations or cash flows.

Recently Issued Accounting Pronouncements

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. During 2016, the FASB issued four ASUs that address implementation issues and correct or improve certain aspects of the new revenue recognition guidance, including ASU 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross versus Net), ASU 2016-10, Identifying Performance Obligations and Licensing, ASU 2016-12, Narrow-Scope Improvements and Practical Expedients and ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers. These ASUs do not change the core principles in the revenue recognition standard outlined above. The Company has developed a multiphase plan and established a cross-functional team to evaluate and implement the new standard. Management has completed the diagnostic phase, which involved reviewing various customer contracts and comparing current accounting to the requirements of the new standard. Currently management is evaluating the new disclosure requirements and identifying and implementing appropriate changes to its business processes and controls to support recognition and disclosure under the new standard. The new standard will be adopted in the first quarter of 2018 and the Company expects to use the modified retrospective approach. Management will continue to evaluate the impact that this pronouncement may have on WESCO's consolidated financial statements and notes thereto.

In February 2016, the FASB issued ASU 2016-02, Leases, a comprehensive new standard that amends various aspects of existing accounting guidance for leases, including the recognition of a right-of-use asset and a lease liability on the balance sheet and disclosing key information about leasing arrangements. This guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The new leasing standard requires modified retrospective transition, which requires application of the new guidance at the beginning of the earliest comparative period presented in the year of adoption. Management is currently evaluating the impact of this new standard on WESCO's consolidated financial statements and notes thereto.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which introduces new guidance for the accounting for credit losses on certain financial instruments. The amendments in ASU 2016-13 are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years and early adoption is permitted. Management is currently evaluating the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force). This ASU provides guidance on eight specific cash flow issues where there is diversity in practice. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. Management is currently evaluating the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In January 2017, the FASB issued ASU 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, which eliminates Step 2 from the goodwill impairment test. Under the amendments in this update, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. An entity should apply the amendments in this ASU on a prospective basis. This guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Management has not yet evaluated the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In March 2017, the FASB issued ASU 2017-07, Compensation—Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. Presently, net benefit cost is reported as an employee cost within operating income (or capitalized into assets when appropriate). This amendment requires the bifurcation of net benefit cost. The service component will be presented with other employee compensation costs in operating income (or capitalized in assets). The other components will be reported separately outside of operations, and will not be eligible for capitalization. This guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. Management has not yet evaluated the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting, which clarifies when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new guidance, modification accounting is required only if the fair value, the vesting conditions, or the classification of the award (as equity or liability) changes as a result of the change in terms or conditions. The guidance is effective prospectively for all companies for annual periods beginning on or after December 15, 2017. Early adoption is permitted. Management has not yet evaluated the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

Other pronouncements issued by the FASB or other authoritative accounting standards groups with future effective dates are either not applicable or are not expected to be significant to WESCO’s financial position, results of operations or cash flows.

Fair Value of Financial Instruments

The Company’s financial instruments consist of cash and cash equivalents, accounts receivable, accounts payable and other accrued liabilities, and outstanding indebtedness. The reported carrying amounts of WESCO’s financial 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.

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ACQUISITIONS

9 Months Ended

Sep. 30, 2017

Business Combinations [Abstract]

ACQUISITIONS

3. ACQUISITIONS

On March 14, 2016, WESCO Distribution, Inc. ("WESCO Distribution") completed the acquisition of Atlanta Electrical Distributors, LLC ("AED"), an Atlanta-based electrical distributor focused on the construction and MRO markets from five locations in Georgia with approximately $85 million in annual sales. WESCO Distribution funded the purchase price paid at closing with borrowings under its 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. In addition to the cash paid at closing, the purchase price included a contingent payment that may be earned upon the achievement of certain financial performance targets over three consecutive one year periods. The fair value of the contingent consideration was determined using a probability-weighted outcome analysis and Level 3 inputs such as internal forecasts. This amount was accrued at the maximum potential payout under the terms of the purchase agreement. The fair value of intangibles was estimated by management and the allocation resulted in intangible assets of $21.8 million and goodwill of $30.0 million. The intangible assets include customer relationships of $15.8 million amortized over 13 and 14 years, a trademark of $6.0 million amortized over 13 years, and non-compete agreements of less than $0.1 million amortized over 5 years. No residual value was estimated for the intangible assets being amortized. The majority of goodwill is deductible for tax purposes.

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STOCK-BASED COMPENSATION

9 Months Ended

Sep. 30, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

STOCK-BASED COMPENSATION

5. 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 endedSeptember 30, 2017 and 2016, WESCO granted the following stock-settled stock appreciation rights, restricted stock units and performance-based awards at the following weighted-average fair values:

	Three Months Ended				Nine Months Ended
	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Stock-settled stock appreciation rights granted	12,076		1,745		455,807		709,999
Weighted-average fair value	$	15.74	$	16.68	$	20.52	$	12.91
Restricted stock units granted	2,313		—		100,993		143,305
Weighted-average fair value	$	57.30	$	—	$	71.33	$	42.45
Performance-based awards granted	—		—		39,978		91,768
Weighted-average fair value	$	—	$	—	$	76.63	$	47.00

The fair value of stock-settled stock appreciation rights was estimated using the following weighted-average assumptions:

	Three Months Ended				Nine Months Ended
	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Risk free interest rate	1.8	%	1.3	%	1.9	%	1.2	%
Expected life (in years)	5		5		5		5
Expected volatility	28	%	31	%	29	%	32	%

The risk-free interest rate is based on the U.S. Treasury Daily Yield Curve rate 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, 2017:

	Awards		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In years)	Aggregate Intrinsic Value (In thousands)
Outstanding at December 31, 2016	2,439,487		$	52.62
Granted	455,807		71.21
Exercised	(472,873	)	42.41
Forfeited	(143,506	)	66.21
Outstanding at September 30, 2017	2,278,915		57.60		6.4	$	18,344
Exercisable at September 30, 2017	1,359,744		$	56.71	4.8	$	12,212

The following table sets forth a summary of time-based restricted stock units and related information for the nine months ended September 30, 2017:

	Awards		Weighted- Average Fair Value
Unvested at December 31, 2016	257,096		$	57.47
Granted	100,993		71.33
Vested	(43,780	)	85.13
Forfeited	(18,022	)	55.96
Unvested at September 30, 2017	296,287		$	58.20

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, 2017:

	Awards		Weighted- Average Fair Value
Unvested at December 31, 2016	149,320		$	60.36
Granted	39,978		76.63
Vested	—		—
Forfeited	(39,650	)	77.40
Unvested at September 30, 2017	149,648		$	60.19

The fair value of the performance shares granted during the nine months ended September 30, 2017 and 2016 was estimated using the following weighted-average assumptions:

	Nine Months Ended
	September 30, 2017			September 30, 2016
Grant date share price	$	71.65		$	42.44
WESCO expected volatility	29		%	26		%
Peer group median volatility	24		%	24		%
Risk-free interest rate	1.5		%	0.9		%
Correlation of peer company returns	114		%	122		%

The unvested performance-based awards in the table above include 74,824 shares in which vesting of the ultimate number of shares 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 74,824 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 $3.5 million and $3.4 million of non-cash stock-based compensation expense, which is included in selling, general and administrative expenses, for the three months ended September 30, 2017 and 2016, respectively. WESCO recognized $11.3 million and $10.4 million of non-cash stock-based compensation expense, which is included in selling, general and administrative expenses, for the nine months ended September 30, 2017 and 2016, respectively. As of September 30, 2017, there was $22.6 million of total unrecognized compensation cost related to non-vested stock-based compensation arrangements for all awards previously made, of which approximately $3.7 million is expected to be recognized over the remainder of 2017, $11.4 million in 2018, $6.7 million in 2019 and $0.8 million in 2020.

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EARNINGS PER SHARE

9 Months Ended

Sep. 30, 2017

Earnings Per Share [Abstract]

EARNINGS PER SHARE

6. EARNINGS PER SHARE

Basic earnings per share is computed by dividing net income attributable to WESCO International by the weighted-average number of common shares outstanding during the periods. Diluted earnings per share is computed by dividing net income attributable to WESCO International 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 equity awards and contingently convertible debt.

The following table sets forth the details of basic and diluted earnings per share:

	Three Months Ended					Nine Months Ended
	September 30,					September 30,
(In thousands, except per share data)	2017		2016			2017		2016
Net income (loss) attributable to WESCO International, Inc.	$	53,675	$	(31,611	)	$	140,918	$	54,243
Weighted-average common shares outstanding used in computing basic earnings per share	47,415		43,378			48,134		42,611
Common shares issuable upon exercise of dilutive equity awards	389		511			508		519
Common shares issuable from contingently convertible debentures (see below for basis of calculation)	—		4,851			—		4,908
Weighted-average common shares outstanding and common share equivalents, diluted	47,804		48,740			48,642		48,038
Weighted-average common shares outstanding and common share equivalents used in computing diluted earnings per share	47,804		43,378			48,642		48,038
Earnings (loss) per share attributable to WESCO International, Inc.
Basic	$	1.13	$	(0.73	)	$	2.93	$	1.27
Diluted	$	1.12	$	(0.73	)	$	2.90	$	1.13

For the three and nine months endedSeptember 30, 2017, the computation of diluted earnings per share attributable to WESCO International, Inc. excluded stock-based awards of approximately 1.5 million and 1.3 million, respectively. For the three and nine months endedSeptember 30, 2016, the computation of diluted (loss) earnings per share attributable to WESCO International, Inc. excluded stock-based awards of approximately 1.3 million. These amounts were excluded because their effect would have been antidilutive.

Because of WESCO’s previous obligation to settle the par value of the 6.0% Convertible Senior Debentures due 2029 (the "2029 Debentures") in cash upon conversion, WESCO was 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 exceeded the conversion price of the debentures. Only the number of shares that would have been issuable under the treasury stock method of accounting for share dilution were included, which was based upon the amount by which the average stock price exceeded the conversion price. The conversion price of the 2029 Debentures was $28.87 and the maximum amount of share dilution was limited to 11,951,932 shares. Since the 2029 Debentures were redeemed on September 15, 2016, there was no dilution from contingently convertible debentures for the three and nine months endedSeptember 30, 2017. As a result of the net loss attributable to WESCO International, Inc. for the three months ended September 30, 2016, dilutive shares were not included in the calculation of diluted loss per share because their effect was antidilutive. For the nine months ended September 30, 2016, the effect of the 2029 Debentures on diluted earnings per share attributable to WESCO International, Inc. was a decrease of $0.13.

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. As of December 31, 2016, WESCO had repurchased 2,468,576 shares of the Company's common stock for $150.0 million under this repurchase authorization. During the three months ended June 30, 2017, the Company repurchased 804,291 shares under the repurchase authorization for $50.0 million. On August 7, 2017, the Company entered into an accelerated stock repurchase agreement (the "ASR Transaction") with a financial institution to repurchase additional shares of its common stock. In exchange for an up-front cash payment of $50.0 million, the Company received 974,246 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 the Company's revolving credit facility and accounts receivable securitization facility. For purposes of computing earnings per share, share repurchases have been reflected as a reduction to common shares outstanding on the respective delivery dates.

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EMPLOYEE BENEFIT PLANS

9 Months Ended

Sep. 30, 2017

Retirement Benefits [Abstract]

EMPLOYEE BENEFIT PLANS

7. 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 matches contributions made by employees at an amount equal to 50% of participants' total monthly contributions up to a maximum of 6% of eligible compensation. For Canadian participants, WESCO makes contributions in amounts ranging from 3% to 5% of the participants' eligible compensation based on years of continuous service. WESCO may also make, subject to the Board of Directors' approval, a discretionary contribution to the defined contribution retirement savings plan covering U.S. participants if certain predetermined profit levels are attained. For the nine months ended September 30, 2017 and 2016, WESCO incurred charges of $20.3 million and $18.1 million, respectively, for all such plans. Contributions are made in cash to employee retirement savings plan accounts. The deferred compensation plan is an unfunded plan. As of September 30, 2017 and December 31, 2016, the Company's obligation under the deferred compensation plan was $23.4 million and $21.7 million, respectively. 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 defined benefit plans:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
(In thousands of dollars)	2017			2016			2017			2016
Service cost	$	1,118		$	977		$	3,234		$	2,889
Interest cost	1,007			979			2,915			2,898
Expected return on plan assets	(1,432		)	(1,353		)	(4,144		)	(4,004		)
Recognized actuarial gain	(51		)	(10		)	(149		)	(31		)
Net periodic benefit cost	$	642		$	593		$	1,856		$	1,752

During the three and nine months endedSeptember 30, 2017, there were no employer contributions to the defined benefit plans. During the three and nine months endedSeptember 30, 2016, the Company made aggregate cash contributions of $0.5 million and $1.4 million, respectively, to the defined benefit plans.

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COMMITMENTS AND CONTINGENCIES

9 Months Ended

Sep. 30, 2017

Commitments and Contingencies Disclosure [Abstract]

COMMITMENTS AND CONTINGENCIES

8. COMMITMENTS AND CONTINGENCIES

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 is undergoing a compliance audit in the State of Delaware concerning the identification, reporting and escheatment of unclaimed or abandoned property. The third party auditor conducting the audit on behalf of the State has completed the audit fieldwork and provided a draft of its preliminary findings to the Company and the State for review. A final report is expected to be issued at some point in the future. 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, and is evaluating its alternatives under applicable laws and regulations. If the Company and State do not reach resolution after further discussion, the State may issue 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 is cooperating 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. The Company has recorded a liability for the matter based on the facts currently known to the Company.

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INCOME TAXES

9 Months Ended

Sep. 30, 2017

Income Tax Disclosure [Abstract]

INCOME TAXES

9. INCOME TAXES

The effective tax rate for the three and nine months endedSeptember 30, 2017 was 25.5% and 25.3%, respectively. The effective tax rate for the three and nine months endedSeptember 30, 2016 was 40.5% and 20.4%, respectively. The effective tax rates for the three and nine months endedSeptember 30, 2016 were impacted by the redemption of the 2029 Debentures on September 15, 2016. WESCO’s effective tax rate is typically lower than the federal statutory rate of 35% due to benefits resulting from the tax effect of intercompany financing and lower tax rates on foreign earnings, which are partially offset by nondeductible expenses and state taxes. The current year's effective tax rate is impacted by favorable discrete items, including a benefit from the exercise and vesting of stock-based awards, as well as the mix of income earned in jurisdictions with lower tax rates.

The total amount of unrecognized tax benefits was reduced by $1.6 million during the nine months ended September 30, 2017 to $4.6 million due to the expiration of statutes of limitation and the settlement of state audits. At September 30, 2017, the amount of unrecognized tax benefits that could affect the effective tax rate if recognized in the consolidated financial statements was $6.0 million. Within the next twelve months, it is reasonably possible that the amount of unrecognized tax benefits will decrease by approximately $0.2 million due to the expiration of statutes of limitation and the settlement of state audits. Of this amount, $0.2 million could impact the effective tax rate.

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OTHER FINANCIAL INFORMATION

9 Months Ended

Sep. 30, 2017

Condensed Financial Information [Abstract]

OTHER FINANCIAL INFORMATION

10. CONDENSED CONSOLIDATING FINANCIAL INFORMATION

WESCO Distribution has outstanding $500 million in aggregate principal amount of 5.375% Senior Notes due 2021 (the "2021 Notes") and $350 million in aggregate principal amount of 5.375% Senior Notes due 2024 (the "2024 Notes"). The 2021 Notes and 2024 Notes are unsecured senior obligations of WESCO Distribution and are fully and unconditionally guaranteed on a senior unsecured basis by WESCO International.

Condensed consolidating financial information for WESCO International, WESCO Distribution and the non-guarantor subsidiaries is presented in the following tables.

	Condensed Consolidating Balance Sheet
	September 30, 2017
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.		Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Cash and cash equivalents	$	—	$	45,775	$	48,308		$	—		$	94,083
Trade accounts receivable, net	—		—		1,236,612			—			1,236,612
Inventories	—		403,752		521,297			—			925,049
Prepaid expenses and other current assets	13,642		42,130		203,991			(105,380		)	154,383
Total current assets	13,642		491,657		2,010,208			(105,380		)	2,410,127
Intercompany receivables, net	—		—		2,141,945			(2,141,945		)	—
Property, buildings and equipment, net	—		50,191		107,400			—			157,591
Intangible assets, net	—		2,932		375,221			—			378,153
Goodwill	—		257,623		1,519,295			—			1,776,918
Investments in affiliates	3,817,521		4,228,307		—			(8,045,828		)	—
Other assets	—		18,615		23,064			—			41,679
Total assets	$	3,831,163	$	5,049,325	$	6,177,133		$	(10,293,153	)	$	4,764,468
Accounts payable	$	—	$	443,675	$	394,752		$	—		$	838,427
Short-term debt	—		—		39,712			—			39,712
Other current liabilities	—		117,701		153,033			(105,380		)	165,354
Total current liabilities	—		561,376		587,497			(105,380		)	1,043,493
Intercompany payables, net	1,707,926		434,019		—			(2,141,945		)	—
Long-term debt, net	—		968,361		399,940			—			1,368,301
Other noncurrent liabilities	12,733		61,635		171,073			—			245,441
Total WESCO International, Inc. stockholders' equity	2,110,504		3,023,934		5,021,894			(8,045,828		)	2,110,504
Noncontrolling interests	—		—		(3,271		)	—			(3,271		)
Total liabilities and stockholders’ equity	$	3,831,163	$	5,049,325	$	6,177,133		$	(10,293,153	)	$	4,764,468

	Condensed Consolidating Balance Sheet
	December 31, 2016
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.		Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Cash and cash equivalents	$	—	$	41,552	$	68,579		$	—		$	110,131
Trade accounts receivable, net	—		—		1,034,402			—			1,034,402
Inventories	—		364,562		456,879			—			821,441
Prepaid expenses and other current assets	13,647		34,833		211,637			(123,013		)	137,104
Total current assets	13,647		440,947		1,771,497			(123,013		)	2,103,078
Intercompany receivables, net	—		—		2,060,336			(2,060,336		)	—
Property, buildings and equipment, net	—		51,824		105,783			—			157,607
Intangible assets, net	—		3,417		389,945			—			393,362
Goodwill	—		257,623		1,473,327			—			1,730,950
Investments in affiliates	3,538,476		4,028,502		—			(7,566,978		)	—
Other assets	—		23,846		22,998			—			46,844
Total assets	$	3,552,123	$	4,806,159	$	5,823,886		$	(9,750,327	)	$	4,431,841
Accounts payable	$	—	$	381,795	$	302,926		$	—		$	684,721
Short-term debt	—		—		20,920			—			20,920
Other current liabilities	—		120,299		170,872			(123,013		)	168,158
Total current liabilities	—		502,094		494,718			(123,013		)	873,799
Intercompany payables, net	1,572,486		487,850		—			(2,060,336		)	—
Long-term debt, net	—		983,449		379,686			—			1,363,135
Other noncurrent liabilities	12,737		55,898		162,641			—			231,276
Total WESCO International, Inc. stockholders' equity	1,966,900		2,776,868		4,790,110			(7,566,978		)	1,966,900
Noncontrolling interests	—		—		(3,269		)	—			(3,269		)
Total liabilities and stockholders’ equity	$	3,552,123	$	4,806,159	$	5,823,886		$	(9,750,327	)	$	4,431,841

	Condensed Consolidating Statement of Income and Comprehensive Income
	Three Months Ended
	September 30, 2017
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—	$	867,973		$	1,169,377		$	(37,191	)	$	2,000,159
Cost of goods sold (excluding depreciation and
amortization)	—		697,896			954,109			(37,191		)	1,614,814
Selling, general and administrative expenses	—		140,638			139,383			—			280,021
Depreciation and amortization	—		4,475			11,599			—			16,074
Results of affiliates’ operations	53,576		42,726			—			(96,302		)	—
Interest expense (income), net	—		25,436			(8,125		)	—			17,311
Income tax (benefit) expense	—		(136		)	18,499			—			18,363
Net income	53,576		42,390			53,912			(96,302		)	53,576
Net income attributable to noncontrolling interests	—		—			(99		)	—			(99		)
Net income attributable to WESCO International, Inc.	$	53,576	$	42,390		$	54,011		$	(96,302	)	$	53,675
Other comprehensive income:
Foreign currency translation adjustments	51,148		51,148			51,148			(102,296		)	51,148
Comprehensive income attributable to WESCO International, Inc.	$	104,724	$	93,538		$	105,159		$	(198,598	)	$	104,823

	Condensed Consolidating Statement of (Loss) Income and Comprehensive (Loss) Income
	Three Months Ended
	September 30, 2016
(In thousands of dollars)	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—		$	827,648		$	1,052,915		$	(25,351	)	$	1,855,212
Cost of goods sold (excluding depreciation and
amortization)	—			663,159			852,365			(25,351		)	1,490,173
Selling, general and administrative expenses	38			128,514			126,995			—			255,547
Depreciation and amortization	—			5,114			11,823			—			16,937
Results of affiliates’ operations	100,295			71,567			—			(171,862		)	—
Interest expense (income), net	4,904			23,543			(7,655		)	—			20,792
Loss on debt redemption	123,933			—			—			—			123,933
Income tax expense (benefit)	2,441			(12,261		)	(11,329		)	—			(21,149		)
Net (loss) income	(31,021		)	91,146			80,716			(171,862		)	(31,021		)
Net income attributable to noncontrolling interests	—			—			590			—			590
Net (loss) income attributable to WESCO International, Inc.	$	(31,021	)	$	91,146		$	80,126		$	(171,862	)	$	(31,611	)
Other comprehensive loss:
Foreign currency translation adjustments	(13,993		)	(13,993		)	(13,993		)	27,986			(13,993		)
Comprehensive (loss) income attributable to WESCO International, Inc.	$	(45,014	)	$	77,153		$	66,133		$	(143,876	)	$	(45,604	)

	Condensed Consolidating Statement of Income and Comprehensive Income
	Nine Months Ended
	September 30, 2017
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—	$	2,490,102		$	3,289,693		$	(97,420	)	$	5,682,375
Cost of goods sold (excluding depreciation and
amortization)	—		2,002,708			2,675,608			(97,420		)	4,580,896
Selling, general and administrative expenses	—		410,624			403,651			—			814,275
Depreciation and amortization	—		13,811			33,947			—			47,758
Results of affiliates’ operations	140,915		117,907			—			(258,822		)	—
Interest expense (income), net	—		74,961			(24,114		)	—			50,847
Income tax (benefit) expense	—		(3,034		)	50,718			—			47,684
Net income	140,915		108,939			149,883			(258,822		)	140,915
Net income attributable to noncontrolling interests	—		—			(3		)	—			(3		)
Net income attributable to WESCO International, Inc.	$	140,915	$	108,939		$	149,886		$	(258,822	)	$	140,918
Other comprehensive income:
Foreign currency translation adjustments	96,097		96,097			96,097			(192,194		)	96,097
Post retirement benefit plan adjustments	252		252			252			(504		)	252
Comprehensive income attributable to WESCO International, Inc.	$	237,264	$	205,288		$	246,235		$	(451,520	)	$	237,267

	Condensed Consolidating Statement of Income and Comprehensive Income
	Nine Months Ended
	September 30, 2016
(In thousands of dollars)	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—		$	2,481,165		$	3,140,011		$	(78,421	)	$	5,542,755
Cost of goods sold (excluding depreciation and
amortization)	—			1,985,639			2,535,861			(78,421		)	4,443,079
Selling, general and administrative expenses	(328		)	351,663			448,021			—			799,356
Depreciation and amortization	—			15,318			34,951			—			50,269
Results of affiliates’ operations	193,266			105,401			—			(298,667		)	—
Interest expense (income), net	17,555			63,247			(21,729		)	—			59,073
Loss on debt redemption	123,933			—			—			—			123,933
Income tax (benefit) expense	(1,261		)	4,677			10,262			—			13,678
Net income	53,367			166,022			132,645			(298,667		)	53,367
Net loss attributable to noncontrolling interests	—			—			(876		)	—			(876		)
Net income attributable to WESCO International, Inc.	$	53,367		$	166,022		$	133,521		$	(298,667	)	$	54,243
Other comprehensive income (loss):
Foreign currency translation adjustments	66,512			66,512			66,512			(133,024		)	66,512
Post retirement benefit plan adjustments	(16		)	(16		)	(16		)	32			(16		)
Comprehensive income attributable to WESCO International, Inc.	$	119,863		$	232,518		$	200,017		$	(431,659	)	$	120,739

	Condensed Consolidating Statement of Cash Flows
	Nine Months Ended
	September 30, 2017
(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	$	(28,740	)	$	168,603		$	(58,752	)	$	—		$	81,111
Investing activities:
Capital expenditures	—			(7,435		)	(8,535		)	—			(15,970		)
Dividends received from subsidiaries	—			51,561			—			(51,561		)	—
Other	—			(174,032		)	16,711			160,811			3,490
Net cash (used in) provided by investing activities	—			(129,906		)	8,176			109,250			(12,480		)
Financing activities:
Borrowings	135,442			557,391			691,682			(173,907		)	1,210,608
Repayments	—			(587,485		)	(617,301		)	13,096			(1,191,690		)
Repurchases of common stock	(106,702		)	—			—			—			(106,702		)
Dividends paid by subsidiaries	—			—			(51,561		)	51,561			—
Other	—			(4,380		)	—			—			(4,380		)
Net cash provided by (used in) financing activities	28,740			(34,474		)	22,820			(109,250		)	(92,164		)
Effect of exchange rate changes on cash and cash equivalents	—			—			7,485			—			7,485
Net change in cash and cash equivalents	—			4,223			(20,271		)	—			(16,048		)
Cash and cash equivalents at the beginning of period	—			41,552			68,579			—			110,131
Cash and cash equivalents at the end of period	$	—		$	45,775		$	48,308		$	—		$	94,083

	Condensed Consolidating Statement of Cash Flows
	Nine Months Ended
	September 30, 2016
(In thousands of dollars)	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net cash provided by (used in) operating activities	$	124,834		$	(274,575	)	$	366,929		$	—		$	217,188
Investing activities:
Capital expenditures	—			(9,224		)	(3,959		)	—			(13,183		)
Acquisition payments, net of cash acquired	—			(50,745		)	—			—			(50,745		)
Dividends received from subsidiaries	—			47,621			—			(47,621		)	—
Other	—			(257,768		)	(335,594		)	589,477			(3,885		)
Net cash used in investing activities	—			(270,116		)	(339,553		)	541,856			(67,813		)
Financing activities:
Borrowings	224,043			1,386,397			468,890			(257,768		)	1,821,562
Repayments	(344,804		)	(834,688		)	(500,879		)	(331,709		)	(2,012,080		)
Dividends paid by subsidiaries	—			—			(47,621		)	47,621			—
Other	(4,073		)	(3,494		)	—			—			(7,567		)
Net cash (used in) provided by financing activities	(124,834		)	548,215			(79,610		)	(541,856		)	(198,085		)
Effect of exchange rate changes on cash and cash equivalents	—			—			1,268			—			1,268
Net change in cash and cash equivalents	—			3,524			(50,966		)	—			(47,442		)
Cash and cash equivalents at the beginning of period	—			38,963			121,316			—			160,279
Cash and cash equivalents at the end of period	$	—		$	42,487		$	70,350		$	—		$	112,837

Revisions

As described in Note 2, the Condensed Consolidated Balance Sheet at December 31, 2016 has been revised to correct certain financial statement line items.

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Subsequent Events SUBSEQUENT EVENTS (Notes)

9 Months Ended

Sep. 30, 2017

Subsequent Events [Abstract]

Subsequent Events [Text Block]

11. SUBSEQUENT EVENTS

The Company evaluated subsequent events and concluded that no subsequent events have occurred that would require recognition in the unaudited Condensed Consolidated Financial Statements or disclosure in the Notes thereto.

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GOODWILL (Notes)

9 Months Ended

Sep. 30, 2017

Goodwill [Line Items]

Goodwill Disclosure [Text Block]

4. GOODWILL

The following table sets forth the changes in the carrying value of goodwill:

	Nine Months Ended
	September 30, 2017		September 30, 2016
	(In thousands)
Beginning balance January 1(1)	$	1,730,950	$	1,681,662
Foreign currency exchange rate changes	45,968		34,799
Adjustments to goodwill for acquisitions (2)	—		19,201
Ending balance September 30	$	1,776,918	$	1,735,662

⁽¹⁾ As described in Note 2, the Condensed Consolidated Balance Sheet at December 31, 2016 has been revised to correct certain financial statement line items, including goodwill.

⁽²⁾ For the nine months ended September 30, 2016, adjustments relate to goodwill resulting from the preliminary allocation of the AED purchase price to the respective assets acquired and liabilities assumed, partially offset by an adjustment to goodwill related to deferred income taxes.

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ACCOUNTING POLICIES (Policies)

9 Months Ended

Sep. 30, 2017

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 2016 Annual Report on Form 10-K as filed with the SEC on February 22, 2017. The Condensed Consolidated Balance Sheet at December 31, 2016 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, 2017, the unaudited Condensed Consolidated Statements of Income and Comprehensive Income for the three and nine months ended September 30, 2017 and 2016, respectively, and the unaudited Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2017 and 2016, 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.

Fair Value of Financial Instruments

Fair Value of Financial Instruments

The Company’s financial instruments consist of cash and cash equivalents, accounts receivable, accounts payable and other accrued liabilities, and outstanding indebtedness. The reported carrying amounts of WESCO’s financial 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.

New Accounting Pronouncements, Policy [Policy Text Block]

Recently Adopted Accounting Pronouncements

In March 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, which simplifies several aspects of accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments in this ASU affect all entities that issue share-based payment awards to their employees. The Company adopted this ASU in the first quarter of 2017. The amendment related to the recognition of excess tax benefits and deficiencies was applied prospectively and, as disclosed in Note 9, lowered the Company's effective tax rate for the nine months ended September 30, 2017. The amendment related to the presentation of excess tax benefits on the statement of cash flows was also applied prospectively, and did not have a material impact on WESCO's cash flows. The other amendments, which were adopted by the Company according to the respective transition requirements, had no impact on the consolidated financial statements and notes thereto.

In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory. The purpose of ASU 2016-16 is to simplify the income tax accounting of an intra-entity transfer of an asset other than inventory and to record its effect when the transfer occurs. The Company early adopted this ASU on a modified retrospective basis in the first quarter of 2017. The adoption of this ASU did not have a material impact on WESCO's financial position and it had no impact on its results of operations or cash flows.

Recently Issued Accounting Pronouncements

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. During 2016, the FASB issued four ASUs that address implementation issues and correct or improve certain aspects of the new revenue recognition guidance, including ASU 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross versus Net), ASU 2016-10, Identifying Performance Obligations and Licensing, ASU 2016-12, Narrow-Scope Improvements and Practical Expedients and ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers. These ASUs do not change the core principles in the revenue recognition standard outlined above. The Company has developed a multiphase plan and established a cross-functional team to evaluate and implement the new standard. Management has completed the diagnostic phase, which involved reviewing various customer contracts and comparing current accounting to the requirements of the new standard. Currently management is evaluating the new disclosure requirements and identifying and implementing appropriate changes to its business processes and controls to support recognition and disclosure under the new standard. The new standard will be adopted in the first quarter of 2018 and the Company expects to use the modified retrospective approach. Management will continue to evaluate the impact that this pronouncement may have on WESCO's consolidated financial statements and notes thereto.

In February 2016, the FASB issued ASU 2016-02, Leases, a comprehensive new standard that amends various aspects of existing accounting guidance for leases, including the recognition of a right-of-use asset and a lease liability on the balance sheet and disclosing key information about leasing arrangements. This guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. The new leasing standard requires modified retrospective transition, which requires application of the new guidance at the beginning of the earliest comparative period presented in the year of adoption. Management is currently evaluating the impact of this new standard on WESCO's consolidated financial statements and notes thereto.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which introduces new guidance for the accounting for credit losses on certain financial instruments. The amendments in ASU 2016-13 are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years and early adoption is permitted. Management is currently evaluating the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force). This ASU provides guidance on eight specific cash flow issues where there is diversity in practice. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. Management is currently evaluating the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In January 2017, the FASB issued ASU 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, which eliminates Step 2 from the goodwill impairment test. Under the amendments in this update, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. An entity should apply the amendments in this ASU on a prospective basis. This guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Management has not yet evaluated the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In March 2017, the FASB issued ASU 2017-07, Compensation—Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. Presently, net benefit cost is reported as an employee cost within operating income (or capitalized into assets when appropriate). This amendment requires the bifurcation of net benefit cost. The service component will be presented with other employee compensation costs in operating income (or capitalized in assets). The other components will be reported separately outside of operations, and will not be eligible for capitalization. This guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. Management has not yet evaluated the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting, which clarifies when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new guidance, modification accounting is required only if the fair value, the vesting conditions, or the classification of the award (as equity or liability) changes as a result of the change in terms or conditions. The guidance is effective prospectively for all companies for annual periods beginning on or after December 15, 2017. Early adoption is permitted. Management has not yet evaluated the impact of this accounting standard on WESCO's consolidated financial statements and notes thereto.

Other pronouncements issued by the FASB or other authoritative accounting standards groups with future effective dates are either not applicable or are not expected to be significant to WESCO’s financial position, results of operations or cash flows.

Comparability of Prior Year Financial Data, Policy [Policy Text Block]

Revision of Prior Period Financial Statements

In the third quarter of 2017, management determined that the Company's income taxes receivable and payable and other tax account balances were overstated as of December 31, 2016 by a cumulative net amount of $46.4 million, which related to multiple prior periods. The Company also identified a $10.2 million understatement related to deferred income taxes and goodwill. In accordance with Staff Accounting Bulletin (“SAB”) No. 99, Materiality, and SAB No. 108, Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements, management concluded that these misstatements are not material to the Company's previously issued annual and interim financial statements. Correcting the effected financial statement line items in the quarterly period ended September 30, 2017 would materially misstate the condensed consolidated financial information presented herein. Accordingly, the Condensed Consolidated Balance Sheet at December 31, 2016 in this Quarterly Report on Form 10-Q has been revised. There was an immaterial effect on the Condensed Consolidated Statements of Income and Comprehensive Income for the three and nine months ended September 30, 2016, and no effect on the Condensed Consolidated Statements of Cash Flows for the respective periods presented herein. Periods not presented herein will be revised, as applicable, in future filings.

The following table presents the effects on the financial statement line items that were revised:

	December 31, 2016
	As Reported			Adjustment			As Revised
	(In thousands)
Prepaid expenses and other current assets	$	121,464		$	(69,379	)	$	52,085
Total current assets	2,172,457			(69,379		)	2,103,078
Goodwill	1,720,714			10,236			1,730,950
Total assets	4,490,984			(59,143		)	4,431,841
Other current liabilities	111,304			(22,998		)	88,306
Total current liabilities	896,797			(22,998		)	873,799
Deferred income taxes	158,009			10,236			168,245
Total liabilities	2,480,972			(12,762		)	2,468,210
Retained earnings	1,956,532			(41,775		)	1,914,757
Accumulated other comprehensive loss	(387,365		)	(4,606		)	(391,971		)
Total stockholders' equity	2,010,012			(46,381		)	1,963,631
Total liabilities and stockholders' equity	4,490,984			(59,143		)	4,431,841

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ACCOUNTING POLICIES Revision (Tables)

9 Months Ended

Sep. 30, 2017

Quantifying Misstatement in Current Year Financial Statements [Line Items]

Schedule of Quantifying Prior Year Misstatements Corrected in Current Year Financial Statements [Table Text Block]

The following table presents the effects on the financial statement line items that were revised:

	December 31, 2016
	As Reported			Adjustment			As Revised
	(In thousands)
Prepaid expenses and other current assets	$	121,464		$	(69,379	)	$	52,085
Total current assets	2,172,457			(69,379		)	2,103,078
Goodwill	1,720,714			10,236			1,730,950
Total assets	4,490,984			(59,143		)	4,431,841
Other current liabilities	111,304			(22,998		)	88,306
Total current liabilities	896,797			(22,998		)	873,799
Deferred income taxes	158,009			10,236			168,245
Total liabilities	2,480,972			(12,762		)	2,468,210
Retained earnings	1,956,532			(41,775		)	1,914,757
Accumulated other comprehensive loss	(387,365		)	(4,606		)	(391,971		)
Total stockholders' equity	2,010,012			(46,381		)	1,963,631
Total liabilities and stockholders' equity	4,490,984			(59,143		)	4,431,841

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STOCK-BASED COMPENSATION (Tables)

9 Months Ended

Sep. 30, 2017

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 endedSeptember 30, 2017 and 2016, WESCO granted the following stock-settled stock appreciation rights, restricted stock units and performance-based awards at the following weighted-average fair values:

	Three Months Ended				Nine Months Ended
	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Stock-settled stock appreciation rights granted	12,076		1,745		455,807		709,999
Weighted-average fair value	$	15.74	$	16.68	$	20.52	$	12.91
Restricted stock units granted	2,313		—		100,993		143,305
Weighted-average fair value	$	57.30	$	—	$	71.33	$	42.45
Performance-based awards granted	—		—		39,978		91,768
Weighted-average fair value	$	—	$	—	$	76.63	$	47.00

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, 2017:

	Awards		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In years)	Aggregate Intrinsic Value (In thousands)
Outstanding at December 31, 2016	2,439,487		$	52.62
Granted	455,807		71.21
Exercised	(472,873	)	42.41
Forfeited	(143,506	)	66.21
Outstanding at September 30, 2017	2,278,915		57.60		6.4	$	18,344
Exercisable at September 30, 2017	1,359,744		$	56.71	4.8	$	12,212

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, 2017:

	Awards		Weighted- Average Fair Value
Unvested at December 31, 2016	257,096		$	57.47
Granted	100,993		71.33
Vested	(43,780	)	85.13
Forfeited	(18,022	)	55.96
Unvested at September 30, 2017	296,287		$	58.20

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, 2017:

	Awards		Weighted- Average Fair Value
Unvested at December 31, 2016	149,320		$	60.36
Granted	39,978		76.63
Vested	—		—
Forfeited	(39,650	)	77.40
Unvested at September 30, 2017	149,648		$	60.19

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]

The fair value of stock-settled stock appreciation rights was estimated using the following weighted-average assumptions:

	Three Months Ended				Nine Months Ended
	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Risk free interest rate	1.8	%	1.3	%	1.9	%	1.2	%
Expected life (in years)	5		5		5		5
Expected volatility	28	%	31	%	29	%	32	%

Performance Shares [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]

The fair value of the performance shares granted during the nine months ended September 30, 2017 and 2016 was estimated using the following weighted-average assumptions:

	Nine Months Ended
	September 30, 2017			September 30, 2016
Grant date share price	$	71.65		$	42.44
WESCO expected volatility	29		%	26		%
Peer group median volatility	24		%	24		%
Risk-free interest rate	1.5		%	0.9		%
Correlation of peer company returns	114		%	122		%

XML

EARNINGS PER SHARE (Tables)

9 Months Ended

Sep. 30, 2017

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The following table sets forth the details of basic and diluted earnings per share:

	Three Months Ended					Nine Months Ended
	September 30,					September 30,
(In thousands, except per share data)	2017		2016			2017		2016
Net income (loss) attributable to WESCO International, Inc.	$	53,675	$	(31,611	)	$	140,918	$	54,243
Weighted-average common shares outstanding used in computing basic earnings per share	47,415		43,378			48,134		42,611
Common shares issuable upon exercise of dilutive equity awards	389		511			508		519
Common shares issuable from contingently convertible debentures (see below for basis of calculation)	—		4,851			—		4,908
Weighted-average common shares outstanding and common share equivalents, diluted	47,804		48,740			48,642		48,038
Weighted-average common shares outstanding and common share equivalents used in computing diluted earnings per share	47,804		43,378			48,642		48,038
Earnings (loss) per share attributable to WESCO International, Inc.
Basic	$	1.13	$	(0.73	)	$	2.93	$	1.27
Diluted	$	1.12	$	(0.73	)	$	2.90	$	1.13

XML

EMPLOYEE BENEFIT PLANS Schedule of Net Benefit Costs (Tables)

9 Months Ended

Sep. 30, 2017

Postemployment Benefits [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

The following table reflects the components of net periodic benefit costs for the defined benefit plans:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
(In thousands of dollars)	2017			2016			2017			2016
Service cost	$	1,118		$	977		$	3,234		$	2,889
Interest cost	1,007			979			2,915			2,898
Expected return on plan assets	(1,432		)	(1,353		)	(4,144		)	(4,004		)
Recognized actuarial gain	(51		)	(10		)	(149		)	(31		)
Net periodic benefit cost	$	642		$	593		$	1,856		$	1,752

XML

OTHER FINANCIAL INFORMATION (Tables)

9 Months Ended

Sep. 30, 2017

Condensed Balance Sheet Statements, Captions [Line Items]

Condensed Balance Sheet [Table Text Block]

	Condensed Consolidating Balance Sheet
	December 31, 2016
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.		Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Cash and cash equivalents	$	—	$	41,552	$	68,579		$	—		$	110,131
Trade accounts receivable, net	—		—		1,034,402			—			1,034,402
Inventories	—		364,562		456,879			—			821,441
Prepaid expenses and other current assets	13,647		34,833		211,637			(123,013		)	137,104
Total current assets	13,647		440,947		1,771,497			(123,013		)	2,103,078
Intercompany receivables, net	—		—		2,060,336			(2,060,336		)	—
Property, buildings and equipment, net	—		51,824		105,783			—			157,607
Intangible assets, net	—		3,417		389,945			—			393,362
Goodwill	—		257,623		1,473,327			—			1,730,950
Investments in affiliates	3,538,476		4,028,502		—			(7,566,978		)	—
Other assets	—		23,846		22,998			—			46,844
Total assets	$	3,552,123	$	4,806,159	$	5,823,886		$	(9,750,327	)	$	4,431,841
Accounts payable	$	—	$	381,795	$	302,926		$	—		$	684,721
Short-term debt	—		—		20,920			—			20,920
Other current liabilities	—		120,299		170,872			(123,013		)	168,158
Total current liabilities	—		502,094		494,718			(123,013		)	873,799
Intercompany payables, net	1,572,486		487,850		—			(2,060,336		)	—
Long-term debt, net	—		983,449		379,686			—			1,363,135
Other noncurrent liabilities	12,737		55,898		162,641			—			231,276
Total WESCO International, Inc. stockholders' equity	1,966,900		2,776,868		4,790,110			(7,566,978		)	1,966,900
Noncontrolling interests	—		—		(3,269		)	—			(3,269		)
Total liabilities and stockholders’ equity	$	3,552,123	$	4,806,159	$	5,823,886		$	(9,750,327	)	$	4,431,841

	Condensed Consolidating Balance Sheet
	September 30, 2017
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.		Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Cash and cash equivalents	$	—	$	45,775	$	48,308		$	—		$	94,083
Trade accounts receivable, net	—		—		1,236,612			—			1,236,612
Inventories	—		403,752		521,297			—			925,049
Prepaid expenses and other current assets	13,642		42,130		203,991			(105,380		)	154,383
Total current assets	13,642		491,657		2,010,208			(105,380		)	2,410,127
Intercompany receivables, net	—		—		2,141,945			(2,141,945		)	—
Property, buildings and equipment, net	—		50,191		107,400			—			157,591
Intangible assets, net	—		2,932		375,221			—			378,153
Goodwill	—		257,623		1,519,295			—			1,776,918
Investments in affiliates	3,817,521		4,228,307		—			(8,045,828		)	—
Other assets	—		18,615		23,064			—			41,679
Total assets	$	3,831,163	$	5,049,325	$	6,177,133		$	(10,293,153	)	$	4,764,468
Accounts payable	$	—	$	443,675	$	394,752		$	—		$	838,427
Short-term debt	—		—		39,712			—			39,712
Other current liabilities	—		117,701		153,033			(105,380		)	165,354
Total current liabilities	—		561,376		587,497			(105,380		)	1,043,493
Intercompany payables, net	1,707,926		434,019		—			(2,141,945		)	—
Long-term debt, net	—		968,361		399,940			—			1,368,301
Other noncurrent liabilities	12,733		61,635		171,073			—			245,441
Total WESCO International, Inc. stockholders' equity	2,110,504		3,023,934		5,021,894			(8,045,828		)	2,110,504
Noncontrolling interests	—		—		(3,271		)	—			(3,271		)
Total liabilities and stockholders’ equity	$	3,831,163	$	5,049,325	$	6,177,133		$	(10,293,153	)	$	4,764,468

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OTHER FINANCIAL INFORMATION Condensed Income Statement (Tables)

9 Months Ended

Sep. 30, 2017

Condensed Income Statements, Captions [Line Items]

Condensed Income Statement [Table Text Block]

	Condensed Consolidating Statement of (Loss) Income and Comprehensive (Loss) Income
	Three Months Ended
	September 30, 2016
(In thousands of dollars)	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—		$	827,648		$	1,052,915		$	(25,351	)	$	1,855,212
Cost of goods sold (excluding depreciation and
amortization)	—			663,159			852,365			(25,351		)	1,490,173
Selling, general and administrative expenses	38			128,514			126,995			—			255,547
Depreciation and amortization	—			5,114			11,823			—			16,937
Results of affiliates’ operations	100,295			71,567			—			(171,862		)	—
Interest expense (income), net	4,904			23,543			(7,655		)	—			20,792
Loss on debt redemption	123,933			—			—			—			123,933
Income tax expense (benefit)	2,441			(12,261		)	(11,329		)	—			(21,149		)
Net (loss) income	(31,021		)	91,146			80,716			(171,862		)	(31,021		)
Net income attributable to noncontrolling interests	—			—			590			—			590
Net (loss) income attributable to WESCO International, Inc.	$	(31,021	)	$	91,146		$	80,126		$	(171,862	)	$	(31,611	)
Other comprehensive loss:
Foreign currency translation adjustments	(13,993		)	(13,993		)	(13,993		)	27,986			(13,993		)
Comprehensive (loss) income attributable to WESCO International, Inc.	$	(45,014	)	$	77,153		$	66,133		$	(143,876	)	$	(45,604	)

	Condensed Consolidating Statement of Income and Comprehensive Income
	Three Months Ended
	September 30, 2017
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—	$	867,973		$	1,169,377		$	(37,191	)	$	2,000,159
Cost of goods sold (excluding depreciation and
amortization)	—		697,896			954,109			(37,191		)	1,614,814
Selling, general and administrative expenses	—		140,638			139,383			—			280,021
Depreciation and amortization	—		4,475			11,599			—			16,074
Results of affiliates’ operations	53,576		42,726			—			(96,302		)	—
Interest expense (income), net	—		25,436			(8,125		)	—			17,311
Income tax (benefit) expense	—		(136		)	18,499			—			18,363
Net income	53,576		42,390			53,912			(96,302		)	53,576
Net income attributable to noncontrolling interests	—		—			(99		)	—			(99		)
Net income attributable to WESCO International, Inc.	$	53,576	$	42,390		$	54,011		$	(96,302	)	$	53,675
Other comprehensive income:
Foreign currency translation adjustments	51,148		51,148			51,148			(102,296		)	51,148
Comprehensive income attributable to WESCO International, Inc.	$	104,724	$	93,538		$	105,159		$	(198,598	)	$	104,823

	Condensed Consolidating Statement of Income and Comprehensive Income
	Nine Months Ended
	September 30, 2016
(In thousands of dollars)	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—		$	2,481,165		$	3,140,011		$	(78,421	)	$	5,542,755
Cost of goods sold (excluding depreciation and
amortization)	—			1,985,639			2,535,861			(78,421		)	4,443,079
Selling, general and administrative expenses	(328		)	351,663			448,021			—			799,356
Depreciation and amortization	—			15,318			34,951			—			50,269
Results of affiliates’ operations	193,266			105,401			—			(298,667		)	—
Interest expense (income), net	17,555			63,247			(21,729		)	—			59,073
Loss on debt redemption	123,933			—			—			—			123,933
Income tax (benefit) expense	(1,261		)	4,677			10,262			—			13,678
Net income	53,367			166,022			132,645			(298,667		)	53,367
Net loss attributable to noncontrolling interests	—			—			(876		)	—			(876		)
Net income attributable to WESCO International, Inc.	$	53,367		$	166,022		$	133,521		$	(298,667	)	$	54,243
Other comprehensive income (loss):
Foreign currency translation adjustments	66,512			66,512			66,512			(133,024		)	66,512
Post retirement benefit plan adjustments	(16		)	(16		)	(16		)	32			(16		)
Comprehensive income attributable to WESCO International, Inc.	$	119,863		$	232,518		$	200,017		$	(431,659	)	$	120,739

	Condensed Consolidating Statement of Income and Comprehensive Income
	Nine Months Ended
	September 30, 2017
(In thousands of dollars)	WESCO International, Inc.		WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net sales	$	—	$	2,490,102		$	3,289,693		$	(97,420	)	$	5,682,375
Cost of goods sold (excluding depreciation and
amortization)	—		2,002,708			2,675,608			(97,420		)	4,580,896
Selling, general and administrative expenses	—		410,624			403,651			—			814,275
Depreciation and amortization	—		13,811			33,947			—			47,758
Results of affiliates’ operations	140,915		117,907			—			(258,822		)	—
Interest expense (income), net	—		74,961			(24,114		)	—			50,847
Income tax (benefit) expense	—		(3,034		)	50,718			—			47,684
Net income	140,915		108,939			149,883			(258,822		)	140,915
Net income attributable to noncontrolling interests	—		—			(3		)	—			(3		)
Net income attributable to WESCO International, Inc.	$	140,915	$	108,939		$	149,886		$	(258,822	)	$	140,918
Other comprehensive income:
Foreign currency translation adjustments	96,097		96,097			96,097			(192,194		)	96,097
Post retirement benefit plan adjustments	252		252			252			(504		)	252
Comprehensive income attributable to WESCO International, Inc.	$	237,264	$	205,288		$	246,235		$	(451,520	)	$	237,267

XML

OTHER FINANCIAL INFORMATION Condensed Cash Flow Statement (Tables)

9 Months Ended

Sep. 30, 2017

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, 2016
(In thousands of dollars)	WESCO International, Inc.			WESCO Distribution, Inc.			Non-Guarantor Subsidiaries			Consolidating and Eliminating Entries			Consolidated
Net cash provided by (used in) operating activities	$	124,834		$	(274,575	)	$	366,929		$	—		$	217,188
Investing activities:
Capital expenditures	—			(9,224		)	(3,959		)	—			(13,183		)
Acquisition payments, net of cash acquired	—			(50,745		)	—			—			(50,745		)
Dividends received from subsidiaries	—			47,621			—			(47,621		)	—
Other	—			(257,768		)	(335,594		)	589,477			(3,885		)
Net cash used in investing activities	—			(270,116		)	(339,553		)	541,856			(67,813		)
Financing activities:
Borrowings	224,043			1,386,397			468,890			(257,768		)	1,821,562
Repayments	(344,804		)	(834,688		)	(500,879		)	(331,709		)	(2,012,080		)
Dividends paid by subsidiaries	—			—			(47,621		)	47,621			—
Other	(4,073		)	(3,494		)	—			—			(7,567		)
Net cash (used in) provided by financing activities	(124,834		)	548,215			(79,610		)	(541,856		)	(198,085		)
Effect of exchange rate changes on cash and cash equivalents	—			—			1,268			—			1,268
Net change in cash and cash equivalents	—			3,524			(50,966		)	—			(47,442		)
Cash and cash equivalents at the beginning of period	—			38,963			121,316			—			160,279
Cash and cash equivalents at the end of period	$	—		$	42,487		$	70,350		$	—		$	112,837

	Condensed Consolidating Statement of Cash Flows
	Nine Months Ended
	September 30, 2017
(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	$	(28,740	)	$	168,603		$	(58,752	)	$	—		$	81,111
Investing activities:
Capital expenditures	—			(7,435		)	(8,535		)	—			(15,970		)
Dividends received from subsidiaries	—			51,561			—			(51,561		)	—
Other	—			(174,032		)	16,711			160,811			3,490
Net cash (used in) provided by investing activities	—			(129,906		)	8,176			109,250			(12,480		)
Financing activities:
Borrowings	135,442			557,391			691,682			(173,907		)	1,210,608
Repayments	—			(587,485		)	(617,301		)	13,096			(1,191,690		)
Repurchases of common stock	(106,702		)	—			—			—			(106,702		)
Dividends paid by subsidiaries	—			—			(51,561		)	51,561			—
Other	—			(4,380		)	—			—			(4,380		)
Net cash provided by (used in) financing activities	28,740			(34,474		)	22,820			(109,250		)	(92,164		)
Effect of exchange rate changes on cash and cash equivalents	—			—			7,485			—			7,485
Net change in cash and cash equivalents	—			4,223			(20,271		)	—			(16,048		)
Cash and cash equivalents at the beginning of period	—			41,552			68,579			—			110,131
Cash and cash equivalents at the end of period	$	—		$	45,775		$	48,308		$	—		$	94,083

XML

GOODWILL (Tables)

9 Months Ended

Sep. 30, 2017

Goodwill [Line Items]

Schedule of Goodwill [Table Text Block]

	Nine Months Ended
	September 30, 2017		September 30, 2016
	(In thousands)
Beginning balance January 1(1)	$	1,730,950	$	1,681,662
Foreign currency exchange rate changes	45,968		34,799
Adjustments to goodwill for acquisitions (2)	—		19,201
Ending balance September 30	$	1,776,918	$	1,735,662

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ORGANIZATION (Details)	Sep. 30, 2017 customers countries branches
Restructuring Cost and Reserve [Line Items]
Active customers (in customers) | customers	75,000
Full service branches (in branches) | branches	500
Additional countries (in countries) | countries	14

XML

ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Prepaid expenses and other current assets	$ 71,795
Assets, Current	2,410,127	$ 2,103,078
Goodwill	1,776,918	1,730,950	$ 1,735,662	$ 1,681,662
Liabilities and Equity	4,764,468	4,431,841
Other Accrued Liabilities, Current	87,143
Liabilities, Current	1,043,493	873,799
Assets	4,764,468	4,431,841
Deferred Tax Liabilities, Net, Noncurrent	179,630
Liabilities	2,657,235	2,468,210
Retained earnings	2,056,961
Accumulated other comprehensive income	(295,622)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		(46,381)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 2,107,233	1,963,631
Scenario, Previously Reported [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Prepaid expenses and other current assets		121,464
Assets, Current		2,172,457
Goodwill		1,720,714
Liabilities and Equity		4,490,984
Other Accrued Liabilities, Current		111,304
Liabilities, Current		896,797
Assets		4,490,984
Deferred Tax Liabilities, Net, Noncurrent		158,009
Liabilities		2,480,972
Retained earnings		1,956,532
Accumulated other comprehensive income		(387,365)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		2,010,012
Scenario, Adjustment [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Prepaid expenses and other current assets		(69,379)
Assets, Current		(69,379)
Goodwill		10,236
Liabilities and Equity		(59,143)
Other Accrued Liabilities, Current		(22,998)
Liabilities, Current		(22,998)
Assets		(59,143)
Deferred Tax Liabilities, Net, Noncurrent		10,236
Liabilities		(12,762)
Retained earnings		(41,775)
Accumulated other comprehensive income		(4,606)
Restatement Adjustment [Member]
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Prepaid expenses and other current assets		52,085
Assets, Current		2,103,078
Goodwill		1,730,950
Liabilities and Equity		4,431,841
Other Accrued Liabilities, Current		88,306
Liabilities, Current		873,799
Assets		4,431,841
Deferred Tax Liabilities, Net, Noncurrent		168,245
Liabilities		2,468,210
Retained earnings		1,914,757
Accumulated other comprehensive income		(391,971)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		$ 1,963,631

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ACQUISITIONS - ACQUISITIONS (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) branches	Sep. 30, 2016 USD ($)
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 0	$ 50,745
Number of Stores | branches	500
Atlanta Electrical Distributors, LLC (AED) [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Mar. 14, 2016
Business Acquisition, Name of Acquired Entity	Atlanta Electrical Distributors, LLC
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period	$ 85,000
Finite-lived Intangible Assets Acquired	21,800
Goodwill, Acquired During Period	$ 30,000
Number of Stores	5
Customer Relationships [Member] | Atlanta Electrical Distributors, LLC (AED) [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 15,800
Noncompete Agreements [Member] | Atlanta Electrical Distributors, LLC (AED) [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 100
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years
Trademarks [Member] | Atlanta Electrical Distributors, LLC (AED) [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 6,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	13 years
Minimum [Member] | Customer Relationships [Member] | Atlanta Electrical Distributors, LLC (AED) [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	13 years
Maximum [Member] | Customer Relationships [Member] | Atlanta Electrical Distributors, LLC (AED) [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	14 years

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SCHEDULE OF SHARE-BASED COMPENSATION, STOCK OPTIONS AND STOCK APPRECIATION RIGHTS AWARD ACTIVITY (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
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)			$ 42.41
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			$ 71.21
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 12,212		$ 12,212
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 57.60		$ 57.60		$ 52.62
Share-based Compensation Arrangement By Share-based Payment Award, Options and Stock Appreciation Rights, Outstanding [Roll Forward]
Beginning of Year (in shares)	1,359,744		1,359,744
Grants in Period (in shares)	12,076	1,745	455,807	709,999
Exercises in Period (in shares)			472,873
Forfeitures in Period (in shares)			143,506
Weighted Average Exercise Price, Forfeitures in Period (in dollars per share)			$ 66.21
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 56.71		$ 56.71
Weighted Average Remaining Contractual Term, Outstanding (in years)			6 years 5 months 6 days
Weighted Average Remaining Contractual Term, Exercisable (in years)			4 years 9 months 6 days
Aggregate Intrinsic Value, Outstanding	$ 18,344		$ 18,344
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	2,278,915		2,278,915		2,439,487

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SCHEDULE OF SHARE-BASED PAYMENT AWARD, VALUATION ASSUMPTIONS (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate	1.80%	1.30%	1.90%	1.20%
Expected life (in years)	5 years	5 years	5 years	5 years
WESCO expected volatility	28.00%	31.00%	29.00%	32.00%
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	12,076	1,745	455,807	709,999
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 16	$ 16.68	$ 20.52	$ 12.91
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	2,313	0	100,993	143,305
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 57.30	$ 0.00	$ 71.33	$ 42.45
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	0	0	39,978	91,768
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 0.00	$ 0.00	$ 76.63	$ 47.00
Risk free interest rate			0.00%	0.00%
WESCO expected volatility			0.00%	0.00%

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SUMMARY OF RESTRICTED STOCK UNITS (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested (in shares)	296,287		296,287		257,096
Granted (in shares)	2,313	0	100,993	143,305
Vested (in shares)			(43,780)
Forfeited (in shares)			(18,022)
Unvested, Weighted Average Fair Value (in dollars per share)	$ 58.20		$ 58.20		$ 57.47
Granted, Weighted Average Fair Value (in dollars per share)	$ 57.30	$ 0.00	71.33	$ 42.45
Vested in Period, Weighted Average Fair Value (in dollars per share)			85.13
Forfeited in Period, Weighted Average Fair Value (in dollars per share)			$ 55.96

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SUMMARY OF PERFORMANCE-BASED AWARDS (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested (in shares)	149,648		149,648		149,320
Granted (in shares)	0	0	39,978	91,768
Vested (in shares)			0
Forfeited (in shares)			(39,650)
Unvested, Weighted Average Fair Value (in dollars per share)	$ 60.19		$ 60.19		$ 60.36
Granted, Weighted Average Fair Value (in dollars per share)	$ 0.00	$ 0.00	76.63	$ 47.00
Vested in Period, Weighted Average Fair Value (in dollars per share)			0.00
Forfeited in Period, Weighted Average Fair Value (in dollars per share)			$ 77.40
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)	74,824		74,824

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SCHEDULE OF SHARE-BASED PAYMENT AWARD, PERFORMANCE-BASED AWARDS, VALUATION ASSUMPTIONS (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
WESCO expected volatility	28.00%	31.00%	29.00%	32.00%
Risk free interest rate	1.80%	1.30%	1.90%	1.20%
Correlation			0.00%	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	$ 71.65	$ 42.44	$ 71.65	$ 42.44
WESCO expected volatility			0.00%	0.00%
Risk free interest rate			0.00%	0.00%

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STOCK-BASED COMPENSATION (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 3.5	$ 3.4	$ 11.3	$ 10.4
Total unrecognized compensation cost		$ 22.6		$ 22.6
Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance-based awards outstanding (in shares)		74,824		74,824
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)		74,824		74,824
Scenario, Forecast [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3.7					$ 0.8	$ 6.7	$ 11.4

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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, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net income (loss) attributable to WESCO International, Inc.	$ 53,675	$ (31,611)	$ 140,918	$ 54,243
Weighted average common shares outstanding used in computing basic earnings per share (in shares)	47,415	43,378	48,134	42,611
Common shares issuable upon exercise of dilutive stock options (in shares)	389	511	508	519
Common shares issuable from contingently convertible debentures (in shares)	0	4,851	0	4,908
Weighted average common shares outstanding and common share equivalents used in computing diluted earnings per share (in shares)	47,804	48,740	48,642	48,038
Earnings Per Share, Basic and Diluted [Abstract]
Basic (in dollars per share)	$ 1.13	$ (0.73)	$ 2.93	$ 1.27
Diluted (in dollars per share)	$ 1.12	$ (0.73)	$ 2.90	$ 1.13

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EARNINGS PER SHARE (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Earnings Per Share Dilution Limit (in shares)	0	4,851,000	0	4,908,000
Debt Instrument, Call Date, Earliest			Sep. 15, 2016
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
Dilutive Securities, Effect on Basic Earnings Per Share				$ 0.13
Equity Award [Domain]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,500,000		1,300,000	1,300,000
Convertible Debt Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Earnings Per Share Dilution Limit (in shares)			11,951,932

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EARNINGS PER SHARE Accelerated Share Repurchase (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2015
Accelerated Share Repurchases [Line Items]
Payments for Repurchase of Common Stock			$ (106,702)	$ (4,073)
Stock Repurchase Program, Authorized Amount	$ 300,000		$ 300,000
Stock Repurchase Program Expiration Date			Dec. 31, 2017
Treasury Stock, Common [Member]
Accelerated Share Repurchases [Line Items]
Payments for Repurchase of Common Stock	$ (50,000)	$ (50,000)			$ (150,000)
Treasury Stock, Shares, Acquired	974,246	804,291
Treasury Stock, Common, Shares	2,468,576		2,468,576

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EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Retirement Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 0.5		$ 1.4
Schedule of Employee Benefit Plans [Line Items]
Postemployment Benefits, Period Expense		$ 20.3	$ 18.1
Deferred Compensation Liability, Classified, Noncurrent		$ 23.4		$ 21.7
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 of Match		50.00%
Defined Contribution Plan Employer Matching Contribution Percent		6.00%

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EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS Pension Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Retirement Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Contributions by Employer		$ 500		$ 1,400
Service cost	$ 1,118	977	$ 3,234	2,889
Interest cost	1,007	979	2,915	2,898
Expected return on plan assets	(1,432)	(1,353)	(4,144)	(4,004)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(51)	(10)	(149)	(31)
Net periodic benefit cost	$ 642	$ 593	$ 1,856	$ 1,752

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INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Contingency [Line Items]
Effective tax rate	25.50%	40.53862%	25.30%	20.40122%
Debt Instrument, Call Date, Earliest			Sep. 15, 2016
Federal statutory rate			35.00%
Unrecognized Tax Benefits			$ 1.6
Unrecognized Tax Benefits	$ 4.6		4.6
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	6.0		6.0
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	0.2		0.2
Settlement with Taxing Authority [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 0.2		$ 0.2

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OTHER FINANCIAL INFORMATION (Details) - Unsecured Debt [Member] $ in Millions	Sep. 30, 2017 USD ($)
2021 Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 500
2024 Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 350

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CONDENSED CONSOLIDATED BALANCE SHEETS (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Condensed Financial Information [Line Items]
Cash and cash equivalents	$ 94,083	$ 110,131	$ 112,837	$ 160,279
Trade accounts receivable, net	1,236,612	1,034,402
Inventories, net	925,049	821,441
Prepaid Expense and Other Assets, Current	71,795
Total current assets	2,410,127	2,103,078
Property, buildings and equipment, net	157,591	157,607
Intangible assets, net	378,153	393,362
Goodwill and other intangibles, net	1,776,918	1,730,950	1,735,662	1,681,662
Other assets	41,679	46,844
Total assets	4,764,468	4,431,841
Accounts payable	838,427	684,721
Short-term debt	39,712	20,920
Total current liabilities	1,043,493	873,799
Long-term Debt, Excluding Current Maturities	1,368,301	1,363,135
Total stockholders' equity	2,110,504	1,966,900
Stockholders' Equity Attributable to Noncontrolling Interest	3,271	3,269
Total liabilities and stockholders' equity	4,764,468	4,431,841
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	13,642	13,647
Total current assets	13,642	13,647
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	3,817,521	3,538,476
Other assets	0	0
Total assets	3,831,163	3,552,123
Accounts payable	0	0
Short-term debt	0	0
Other Liabilities, Current	0	0
Total current liabilities	0	0
Intercompany payables, net	1,707,926	1,572,486
Long-term Debt, Excluding Current Maturities	0	0
Liabilities, Other than Long-term Debt, Noncurrent	12,733	12,737
Total stockholders' equity	2,110,504	1,966,900
Stockholders' Equity Attributable to Noncontrolling Interest	0	0
Total liabilities and stockholders' equity	3,831,163	3,552,123
Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Cash and cash equivalents	45,775	41,552	42,487	38,963
Trade accounts receivable, net	0	0
Inventories, net	403,752	364,562
Prepaid Expense and Other Assets, Current	42,130	34,833
Total current assets	491,657	440,947
Intercompany receivables, net	0	0
Property, buildings and equipment, net	50,191	51,824
Intangible assets, net	2,932	3,417
Goodwill and other intangibles, net	257,623	257,623
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	4,228,307	4,028,502
Other assets	18,615	23,846
Total assets	5,049,325	4,806,159
Accounts payable	443,675	381,795
Short-term debt	0	0
Other Liabilities, Current	117,701	120,299
Total current liabilities	561,376	502,094
Intercompany payables, net	434,019	487,850
Long-term Debt, Excluding Current Maturities	968,361	983,449
Liabilities, Other than Long-term Debt, Noncurrent	61,635	55,898
Total stockholders' equity	3,023,934	2,776,868
Stockholders' Equity Attributable to Noncontrolling Interest	0	0
Total liabilities and stockholders' equity	5,049,325	4,806,159
Non-Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Cash and cash equivalents	48,308	68,579	70,350	121,316
Trade accounts receivable, net	1,236,612	1,034,402
Inventories, net	521,297	456,879
Prepaid Expense and Other Assets, Current	203,991	211,637
Total current assets	2,010,208	1,771,497
Intercompany receivables, net	2,141,945	2,060,336
Property, buildings and equipment, net	107,400	105,783
Intangible assets, net	375,221	389,945
Goodwill and other intangibles, net	1,519,295	1,473,327
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Other assets	23,064	22,998
Total assets	6,177,133	5,823,886
Accounts payable	394,752	302,926
Short-term debt	39,712	20,920
Other Liabilities, Current	153,033	170,872
Total current liabilities	587,497	494,718
Intercompany payables, net	0	0
Long-term Debt, Excluding Current Maturities	399,940	379,686
Liabilities, Other than Long-term Debt, Noncurrent	171,073	162,641
Total stockholders' equity	5,021,894	4,790,110
Stockholders' Equity Attributable to Noncontrolling Interest	3,271	3,269
Total liabilities and stockholders' equity	6,177,133	5,823,886
Consolidated Entities [Member]
Condensed Financial Information [Line Items]
Cash and cash equivalents	94,083	110,131	112,837	160,279
Trade accounts receivable, net	1,236,612	1,034,402
Inventories, net	925,049	821,441
Prepaid Expense and Other Assets, Current	154,383	137,104
Total current assets	2,410,127	2,103,078
Intercompany receivables, net	0	0
Property, buildings and equipment, net	157,591	157,607
Intangible assets, net	378,153	393,362
Goodwill and other intangibles, net	1,776,918	1,730,950
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Other assets	41,679	46,844
Total assets	4,764,468	4,431,841
Accounts payable	838,427	684,721
Short-term debt	39,712	20,920
Other Liabilities, Current	165,354	168,158
Total current liabilities	1,043,493	873,799
Intercompany payables, net	0	0
Long-term Debt, Excluding Current Maturities	1,368,301	1,363,135
Liabilities, Other than Long-term Debt, Noncurrent	245,441	231,276
Total stockholders' equity	2,110,504	1,966,900
Stockholders' Equity Attributable to Noncontrolling Interest	3,271	3,269
Total liabilities and stockholders' equity	4,764,468	4,431,841
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	(105,380)	(123,013)
Total current assets	(105,380)	(123,013)
Intercompany receivables, net	(2,141,945)	(2,060,336)
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	(8,045,828)	(7,566,978)
Other assets	0	0
Total assets	(10,293,153)	(9,750,327)
Accounts payable	0	0
Short-term debt	0	0
Other Liabilities, Current	(105,380)	(123,013)
Total current liabilities	(105,380)	(123,013)
Intercompany payables, net	(2,141,945)	(2,060,336)
Long-term Debt, Excluding Current Maturities	0	0
Liabilities, Other than Long-term Debt, Noncurrent	0	0
Total stockholders' equity	(8,045,828)	(7,566,978)
Stockholders' Equity Attributable to Noncontrolling Interest	0	0
Total liabilities and stockholders' equity	$ (10,293,153)	$ (9,750,327)

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CONDENSED CONSOLIDATED INCOME STATEMENTS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Financial Information [Line Items]
Net sales	$ 2,000,159	$ 1,855,212	$ 5,682,375	$ 5,542,755
Cost of goods sold	1,614,814	1,490,173	4,580,896	4,443,079
Selling, general and administrative expense	280,021	255,547	814,275	799,356
Depreciation and amortization	16,074	16,937	47,758	50,269
Gain (Loss) on Extinguishment of Debt	0	(123,933)	0	(123,933)
Provision for income taxes	18,363	(21,149)	47,684	13,678
Net income (loss)	53,576	(31,021)	140,915	53,367
Less: Net (loss) income attributable to noncontrolling interest	(99)	590	(3)	(876)
Net income (loss) attributable to WESCO International, Inc.	53,675	(31,611)	140,918	54,243
Comprehensive Income:
Foreign currency translation adjustment	51,148	(13,993)	96,097	66,512
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	0	0	252	(16)
Comprehensive income attributable to WESCO International, Inc.	104,823	(45,604)	237,267	120,739
Parent Company [Member]
Condensed Financial Information [Line Items]
Net sales	0	0	0	0
Cost of goods sold	0	0	0	0
Selling, general and administrative expense	0	38	0	(328)
Depreciation and amortization	0	0	0	0
Income (Loss) from Subsidiaries, before Tax	53,576	100,295	140,915	193,266
Interest Income (Expense), Net	0	(4,904)	0	(17,555)
Gain (Loss) on Extinguishment of Debt		123,933		123,933
Provision for income taxes	0	2,441	0	(1,261)
Net income (loss)	53,576	(31,021)	140,915	53,367
Less: Net (loss) income attributable to noncontrolling interest	0	0	0	0
Net income (loss) attributable to WESCO International, Inc.	53,576	(31,021)	140,915	53,367
Comprehensive Income:
Foreign currency translation adjustment	51,148	(13,993)	96,097	66,512
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax			(252)	16
Comprehensive income attributable to WESCO International, Inc.	104,724	(45,014)	237,264	119,863
Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Net sales	867,973	827,648	2,490,102	2,481,165
Cost of goods sold	697,896	663,159	2,002,708	1,985,639
Selling, general and administrative expense	140,638	128,514	410,624	351,663
Depreciation and amortization	4,475	5,114	13,811	15,318
Income (Loss) from Subsidiaries, before Tax	42,726	71,567	117,907	105,401
Interest Income (Expense), Net	(25,436)	(23,543)	(74,961)	(63,247)
Gain (Loss) on Extinguishment of Debt		0		0
Provision for income taxes	(136)	(12,261)	(3,034)	4,677
Net income (loss)	42,390	91,146	108,939	166,022
Less: Net (loss) income attributable to noncontrolling interest	0	0	0	0
Net income (loss) attributable to WESCO International, Inc.	42,390	91,146	108,939	166,022
Comprehensive Income:
Foreign currency translation adjustment	51,148	(13,993)	96,097	66,512
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax			(252)	16
Comprehensive income attributable to WESCO International, Inc.	93,538	77,153	205,288	232,518
Non-Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Net sales	1,169,377	1,052,915	3,289,693	3,140,011
Cost of goods sold	954,109	852,365	2,675,608	2,535,861
Selling, general and administrative expense	139,383	126,995	403,651	448,021
Depreciation and amortization	11,599	11,823	33,947	34,951
Income (Loss) from Subsidiaries, before Tax	0	0	0	0
Interest Income (Expense), Net	(8,125)	(7,655)	(24,114)	(21,729)
Gain (Loss) on Extinguishment of Debt		0		0
Provision for income taxes	18,499	(11,329)	50,718	10,262
Net income (loss)	53,912	80,716	149,883	132,645
Less: Net (loss) income attributable to noncontrolling interest	(99)	590	(3)	(876)
Net income (loss) attributable to WESCO International, Inc.	54,011	80,126	149,886	133,521
Comprehensive Income:
Foreign currency translation adjustment	51,148	(13,993)	96,097	66,512
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax			(252)	16
Comprehensive income attributable to WESCO International, Inc.	105,159	66,133	246,235	200,017
Consolidated Entities [Member]
Condensed Financial Information [Line Items]
Net sales	2,000,159	1,855,212	5,682,375	5,542,755
Cost of goods sold	1,614,814	1,490,173	4,580,896	4,443,079
Selling, general and administrative expense	280,021	255,547	814,275	799,356
Depreciation and amortization	16,074	16,937	47,758	50,269
Income (Loss) from Subsidiaries, before Tax	0	0	0	0
Interest Income (Expense), Net	(17,311)	(20,792)	(50,847)	(59,073)
Gain (Loss) on Extinguishment of Debt		123,933		123,933
Provision for income taxes	18,363	(21,149)	47,684	13,678
Net income (loss)	53,576	(31,021)	140,915	53,367
Less: Net (loss) income attributable to noncontrolling interest	(99)	590	(3)	(876)
Net income (loss) attributable to WESCO International, Inc.	53,675	(31,611)	140,918	54,243
Comprehensive Income:
Foreign currency translation adjustment	51,148	(13,993)	96,097	66,512
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax			(252)	16
Comprehensive income attributable to WESCO International, Inc.	104,823	(45,604)	237,267	120,739
Consolidation, Eliminations [Member]
Condensed Financial Information [Line Items]
Net sales	(37,191)	(25,351)	(97,420)	(78,421)
Cost of goods sold	(37,191)	(25,351)	(97,420)	(78,421)
Selling, general and administrative expense	0	0	0	0
Depreciation and amortization	0	0	0	0
Income (Loss) from Subsidiaries, before Tax	(96,302)	(171,862)	(258,822)	(298,667)
Interest Income (Expense), Net	0	0	0	0
Gain (Loss) on Extinguishment of Debt		0		0
Provision for income taxes	0	0	0	0
Net income (loss)	(96,302)	(171,862)	(258,822)	(298,667)
Less: Net (loss) income attributable to noncontrolling interest	0	0	0	0
Net income (loss) attributable to WESCO International, Inc.	(96,302)	(171,862)	(258,822)	(298,667)
Comprehensive Income:
Foreign currency translation adjustment	(102,296)	27,986	(192,194)	(133,024)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax			504	(32)
Comprehensive income attributable to WESCO International, Inc.	$ (198,598)	$ (143,876)	$ (451,520)	$ (431,659)

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CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Condensed Financial Information [Line Items]
Payments for (Proceeds from) Other Investing Activities	$ 3,490	$ (3,885)
Net cash (used) provided by operating activities	81,111	217,188
Investing Activities:
Capital expenditures	(15,970)	(13,183)
Acquisition payments	0	(50,745)
Net cash used in investing activities	(12,480)	(67,813)
Financing Activities:
Payments for Repurchase of Common Stock	(106,702)	(4,073)
Proceeds from (Payments for) Other Financing Activities	(4,380)	(3,494)
Net cash used in financing activities	(92,164)	(198,085)
Effect of exchange rate changes on cash and cash equivalents	7,485	1,268
Net change in cash and cash equivalents	(16,048)	(47,442)
Cash and cash equivalents at the beginning of period	110,131	160,279
Cash and cash equivalents at the end of period	94,083	112,837
Parent Company [Member]
Condensed Financial Information [Line Items]
Payments for (Proceeds from) Other Investing Activities	0	0
Net cash (used) provided by operating activities	(28,740)	124,834
Investing Activities:
Capital expenditures	0	0
Acquisition payments		0
Proceeds from Dividends Received	0	0
Net cash used in investing activities	0	0
Financing Activities:
Borrowings	135,442	224,043
Repayments	0	(344,804)
Cash Dividends Paid to Parent Company	0	0
Payments for Repurchase of Common Stock	106,702
Proceeds from (Payments for) Other Financing Activities	0	(4,073)
Net cash used in financing activities	28,740	(124,834)
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	(174,032)	(257,768)
Net cash (used) provided by operating activities	168,603	(274,575)
Investing Activities:
Capital expenditures	(7,435)	(9,224)
Acquisition payments		(50,745)
Proceeds from Dividends Received	51,561	47,621
Net cash used in investing activities	(129,906)	(270,116)
Financing Activities:
Borrowings	557,391	1,386,397
Repayments	(587,485)	(834,688)
Cash Dividends Paid to Parent Company	0	0
Payments for Repurchase of Private Placement	0
Proceeds from (Payments for) Other Financing Activities	(4,380)	(3,494)
Net cash used in financing activities	(34,474)	548,215
Effect of exchange rate changes on cash and cash equivalents	0	0
Net change in cash and cash equivalents	4,223	3,524
Cash and cash equivalents at the beginning of period	41,552	38,963
Cash and cash equivalents at the end of period	45,775	42,487
Non-Guarantor Subsidiaries [Member]
Condensed Financial Information [Line Items]
Payments for (Proceeds from) Other Investing Activities	16,711	(335,594)
Net cash (used) provided by operating activities	(58,752)	366,929
Investing Activities:
Capital expenditures	(8,535)	(3,959)
Acquisition payments		0
Proceeds from Dividends Received	0	0
Net cash used in investing activities	8,176	(339,553)
Financing Activities:
Borrowings	691,682	468,890
Repayments	(617,301)	(500,879)
Cash Dividends Paid to Parent Company	(51,561)	(47,621)
Payments for Repurchase of Common Stock	0
Proceeds from (Payments for) Other Financing Activities	0	0
Net cash used in financing activities	22,820	(79,610)
Effect of exchange rate changes on cash and cash equivalents	7,485	1,268
Net change in cash and cash equivalents	(20,271)	(50,966)
Cash and cash equivalents at the beginning of period	68,579	121,316
Cash and cash equivalents at the end of period	48,308	70,350
Consolidated Entities [Member]
Condensed Financial Information [Line Items]
Payments for (Proceeds from) Other Investing Activities	3,490	(3,885)
Net cash (used) provided by operating activities	81,111	217,188
Investing Activities:
Capital expenditures	(15,970)	(13,183)
Acquisition payments		(50,745)
Proceeds from Dividends Received	0	0
Net cash used in investing activities	(12,480)	(67,813)
Financing Activities:
Borrowings	1,210,608	1,821,562
Repayments	(1,191,690)	(2,012,080)
Cash Dividends Paid to Parent Company	0	0
Payments for Repurchase of Common Stock	106,702
Proceeds from (Payments for) Other Financing Activities	(4,380)	(7,567)
Net cash used in financing activities	(92,164)	(198,085)
Effect of exchange rate changes on cash and cash equivalents	7,485	1,268
Net change in cash and cash equivalents	(16,048)	(47,442)
Cash and cash equivalents at the beginning of period	110,131	160,279
Cash and cash equivalents at the end of period	94,083	112,837
Consolidation, Eliminations [Member]
Condensed Financial Information [Line Items]
Payments for (Proceeds from) Other Investing Activities	160,811	589,477
Net cash (used) provided by operating activities	0	0
Investing Activities:
Capital expenditures	0	0
Acquisition payments		0
Proceeds from Dividends Received	(51,561)	(47,621)
Net cash used in investing activities	109,250	541,856
Financing Activities:
Borrowings	(173,907)	(257,768)
Repayments	(13,096)	331,709
Cash Dividends Paid to Parent Company	(51,561)	(47,621)
Payments for Repurchase of Common Stock	0
Proceeds from (Payments for) Other Financing Activities	0	0
Net cash used in financing activities	(109,250)	(541,856)
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

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GOODWILL (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Goodwill	$ 1,776,918	$ 1,735,662	$ 1,730,950	$ 1,681,662
Goodwill, Foreign Currency Translation Gain (Loss)	45,968	34,799
Goodwill, Purchase Accounting Adjustments	$ 0	$ 19,201