CDW (CDW) 10-Q 31 Oct 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 28, 2019
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	001-35985
Entity Central Index Key	0001402057
Current Fiscal Year End Date	--12-31
Entity Registrant Name	CDW CORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-0273989
Entity Address, Address Line One	75 Tri-State International
Entity Address, City or Town	Lincolnshire
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60069
City Area Code	847
Local Phone Number	465-6000
Title of 12(b) Security	Common stock, par value $0.01 per share
Trading Symbol	CDW
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		143,680,653
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 166.9	$ 205.8
Accounts receivable, net of allowance for doubtful accounts of $9.1 and $7.0, respectively	2,899.5	2,671.2
Merchandise inventory	603.6	454.3
Miscellaneous receivables	432.2	316.4
Prepaid expenses and other	193.1	149.1
Total current assets	4,295.3	3,796.8
Operating lease right-of-use assets	84.2
Property and equipment, net	171.1	156.1
Goodwill	2,515.9	2,462.8
Other intangible assets, net	616.1	712.2
Other assets	20.5	39.8
Total Assets	7,703.1	7,167.7
Current liabilities:
Accounts payable-trade	1,900	1,577.1
Accounts payable-inventory financing	411.7	429.3
Current maturities of long-term debt	25.4	25.3
Contract liabilities	212.1	178.3
Accrued expenses and other current liabilities:
Compensation	191.4	186.4
Advertising	158	119.2
Sales and income taxes	51.4	55.5
Other	291	232
Total current liabilities	3,241	2,803.1
Long-term liabilities:
Debt	3,259	3,183.3
Deferred income taxes	111.3	141.9
Operating lease liabilities	81.7
Other liabilities	75	64.2
Total long-term liabilities	3,527	3,389.4
Stockholders' equity:
Preferred stock, $0.01 par value, 100.0 shares authorized; no shares issued or outstanding for both periods	0	0
Common stock, $0.01 par value, 1,000.0 shares authorized; 143.9 and 147.7 shares outstanding, respectively	1.4	1.5
Paid-in capital	3,073.2	2,996.9
Accumulated deficit	(1,985.4)	(1,892.6)
Accumulated other comprehensive loss	(154.1)	(130.6)
Total stockholders' equity	935.1	975.2
Total Liabilities and Stockholders' Equity	$ 7,703.1	$ 7,167.7

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) shares in Millions, $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 9.1	$ 7
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	100	100
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000	1,000
Common stock, shares issued (in shares)	143.9	147.7
Common stock, shares outstanding (in shares)	143.9	147.7

Consolidated Statements Of Oper

Consolidated Statements Of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Net sales	$ 4,907.7	$ 4,373.2	$ 13,495.5	$ 12,165.7
Cost of sales	4,091.2	3,659.6	11,233.1	10,152.6
Gross profit	816.5	713.6	2,262.4	2,013.1
Selling and administrative expenses	444.9	390.7	1,269.3	1,134.8
Advertising expense	51	48.1	143.3	133.9
Operating income	320.6	274.8	849.8	744.4
Interest expense, net	(42.3)	(36.6)	(121.1)	(111.5)
Other (expense) income, net	(17.4)	0.2	(15)	1
Income before income taxes	260.9	238.4	713.7	633.9
Income tax expense	(59.2)	(54.7)	(162.5)	(150.2)
Net income	$ 201.7	$ 183.7	$ 551.2	$ 483.7
Net income per common share:
Basic (in dollars per share)	$ 1.39	$ 1.22	$ 3.78	$ 3.19
Diluted (in dollars per share)	$ 1.37	$ 1.20	$ 3.72	$ 3.14
Weighted-average common shares outstanding:
Basic (in shares)	144.5	150.9	145.7	151.6
Diluted (in shares)	147.2	153.7	148.2	154.1

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 201.7	$ 183.7	$ 551.2	$ 483.7
Other comprehensive income (loss):
Unrealized (loss) gain from hedge accounting, net of tax	(0.4)		(12.8)
Unrealized (loss) gain from hedge accounting, net of tax		(1)		3.1
Reclassification of hedge accounting gain to net income, net of tax	0.3		2
Reclassification of hedge accounting gain to net income, net of tax		1.1		2.5
Foreign currency translation, net of tax	(14.6)	(3.2)	(12.7)	(17.9)
Other comprehensive loss	(14.7)	(3.1)	(23.5)	(12.3)
Comprehensive income	$ 187	$ 180.6	$ 527.7	$ 471.4

Consolidated Statement of Share

Consolidated Statement of Shareholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2017		153.1
Beginning balance at Dec. 31, 2017	$ 985.6	$ 1.5	$ 2,911.6	$ (1,831.6)	$ (95.9)
Shareholders' Equity (Deficit) [Roll Forward]
Net income	483.7			483.7
Equity-based compensation expense	26		26
Stock option exercises (in shares)		0.7
Stock option exercises	24.4		24.4
Coworker Stock Purchase Plan (in shares)		0.1
Coworker stock purchase plan	8.4		8.4
Repurchases of common stock (in shares)		(3)
Repurchases of common stock	(232.5)			(232.5)
Dividends paid	(95.5)		0.5	(96)
Incentive compensation plan stock withheld for taxes	(27.1)			(27.1)
Foreign currency translation	(17.9)				(17.9)
Unrealized (loss) gain from hedge accounting	3.1				3.1
Realized gain from hedge accounting	2.5				2.5
Ending balance (in shares) at Sep. 30, 2018		150.9
Ending balance at Sep. 30, 2018	1,160.7	$ 1.5	2,970.9	(1,703.5)	(108.2)
Beginning balance (in shares) at Jun. 30, 2018		151.5
Beginning balance at Jun. 30, 2018	1,068.9	$ 1.5	2,953.3	(1,780.8)	(105.1)
Shareholders' Equity (Deficit) [Roll Forward]
Net income	183.7			183.7
Equity-based compensation expense	9.9		9.9
Stock option exercises (in shares)		0
Stock option exercises	4.5		4.5
Coworker Stock Purchase Plan (in shares)		0
Coworker stock purchase plan	3		3
Repurchases of common stock (in shares)		(0.6)
Repurchases of common stock	(56.1)			(56.1)
Dividends paid	(31.7)		0.2	(31.9)
Incentive compensation plan stock withheld for taxes	(18.4)			(18.4)
Foreign currency translation	(3.2)				(3.2)
Unrealized (loss) gain from hedge accounting	(1)				(1)
Realized gain from hedge accounting	1.1				1.1
Ending balance (in shares) at Sep. 30, 2018		150.9
Ending balance at Sep. 30, 2018	1,160.7	$ 1.5	2,970.9	(1,703.5)	(108.2)
Beginning balance (in shares) at Dec. 31, 2018		147.7
Beginning balance at Dec. 31, 2018	975.2	$ 1.5	2,996.9	(1,892.6)	(130.6)
Shareholders' Equity (Deficit) [Roll Forward]
Net income	551.2			551.2
Equity-based compensation expense	36.9		36.9
Stock option exercises (in shares)		1
Stock option exercises	27.6		27.6
Coworker stock purchase plan	11.2		11.2
Repurchases of common stock (in shares)		(4.8)
Repurchases of common stock	(493.3)	$ (0.1)		(493.2)
Dividends paid	(128.9)		0.6	(129.5)
Incentive compensation plan stock withheld for taxes	(21.3)			(21.3)
Foreign currency translation	(12.7)				(12.7)
Unrealized (loss) gain from hedge accounting	(12.8)				(12.8)
Realized gain from hedge accounting	2				2
Ending balance (in shares) at Sep. 30, 2019		143.9
Ending balance at Sep. 30, 2019	935.1	$ 1.4	3,073.2	(1,985.4)	(154.1)
Beginning balance (in shares) at Jun. 30, 2019		145
Beginning balance at Jun. 30, 2019	936.1	$ 1.5	3,047.6	(1,973.6)	(139.4)
Shareholders' Equity (Deficit) [Roll Forward]
Net income	201.7			201.7
Equity-based compensation expense	12.9		12.9
Stock option exercises (in shares)		0.3
Stock option exercises	8.6		8.6
Coworker stock purchase plan	3.9		3.9
Repurchases of common stock (in shares)		(1.4)
Repurchases of common stock	(161.1)	$ (0.1)		(161)
Dividends paid	(42.6)		0.2	(42.8)
Incentive compensation plan stock withheld for taxes	(9.7)			(9.7)
Foreign currency translation	(14.6)				(14.6)
Unrealized (loss) gain from hedge accounting	(0.4)				(0.4)
Realized gain from hedge accounting	0.3				0.3
Ending balance (in shares) at Sep. 30, 2019		143.9
Ending balance at Sep. 30, 2019	$ 935.1	$ 1.4	$ 3,073.2	$ (1,985.4)	$ (154.1)

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Stockholders' Equity [Abstract]
Dividends (in dollars per share)	$ 0.295	$ 0.210	$ 0.885	$ 0.640

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income	$ 551.2	$ 483.7
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	197.5	198.7
Equity-based compensation expense	37.7	29.9
Deferred income taxes	(33.5)	(39.2)
Other	25.2	8.7
Changes in assets and liabilities:
Accounts receivable	(171.8)	(334.3)
Merchandise inventory	(151.1)	(72.1)
Other assets	(82.2)	(66.1)
Accounts payable-trade	264	300.6
Other liabilities	45.3	92.4
Net cash provided by operating activities	682.3	602.3
Cash flows used in investing activities:
Capital expenditures	(75)	(53.4)
Acquisition of business, net of cash acquired	(75)	0
Net cash used in investing activities	(150)	(53.4)
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	1,860.5	688.9
Repayments of borrowings under revolving credit facility	(1,834.5)	(681.9)
Repayments of long-term debt	(19.7)	(18.2)
Proceeds from issuance of long-term debt	600	0
Payments to extinguish long-term debt	(538.1)	0
Net change in accounts payable-inventory financing	(17.4)	(90.1)
Repurchases of common stock	(493.3)	(232.5)
Payment of incentive compensation plan withholding taxes	(21.3)	(27.1)
Dividend payments	(128.9)	(95.5)
Other	24.2	21.1
Net cash used in financing activities	(568.5)	(435.3)
Effect of exchange rate changes on cash and cash equivalents	(2.7)	(2.7)
Net (decrease) increase in cash and cash equivalents	(38.9)	110.9
Cash and cash equivalents—beginning of period	205.8	144.2
Cash and cash equivalents—end of period	166.9	255.1
Supplementary disclosure of cash flow information:
Interest paid	(124.8)	(117.4)
Taxes paid, net	$ (203)	$ (200.5)

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Description of Business and Summary of Significant Accounting Policies	Description of Business and Summary of Significant Accounting Policies Description of Business CDW Corporation ("Parent"), a Fortune 500 company and member of the S&P 500 Index, is a leading provider of integrated information technology ("IT") solutions with multi-national capabilities to small, medium and large business, government, education and healthcare customers in the United States ("US"), the United Kingdom ("UK") and Canada. The Company's offerings range from discrete hardware and software products to integrated IT solutions such as mobility, security, data center optimization, cloud computing, virtualization and collaboration. Throughout this report, the terms the "Company" and "CDW" refer to Parent and its 100% owned subsidiaries. Parent has two 100% owned subsidiaries, CDW LLC and CDW Finance Corporation. CDW LLC is an Illinois limited liability company that, together with its 100% owned subsidiaries, holds all material assets and conducts all business activities and operations of the Company. CDW Finance Corporation is a Delaware corporation formed for the sole purpose of acting as co-issuer of certain debt obligations as described in Note 13 (Supplemental Guarantor Information) and does not hold any material assets or engage in any business activities or operations. Basis of Presentation The accompanying unaudited interim Consolidated Financial Statements as of September 30, 2019 and for the three and nine months ended September 30, 2019 and 2018 (the "Consolidated Financial Statements") have been prepared in conformity with accounting principles generally accepted in the United States of America ("GAAP") and the rules and regulations of the US Securities and Exchange Commission (the "SEC") for interim financial statements. Accordingly, certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations of the SEC. These Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and the notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2018 (the " December 31, 2018 Consolidated Financial Statements"). The significant accounting policies used in preparing these Consolidated Financial Statements were applied on a basis consistent with those reflected in the December 31, 2018 Consolidated Financial Statements. In the opinion of management, the Consolidated Financial Statements contain all adjustments (consisting of a normal, recurring nature) necessary to present fairly the Company's financial position, results of operations, comprehensive income, cash flows and changes in stockholders' equity as of the dates and for the periods indicated. The unaudited results of operations for such interim periods reported are not necessarily indicative of results for the full year. Principles of Consolidation The accompanying Consolidated Financial Statements include the accounts of Parent and its 100% owned subsidiaries. All intercompany transactions and accounts are eliminated in consolidation. Use of Estimates The preparation of the Consolidated Financial Statements in accordance with GAAP requires management to make use of certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the Consolidated Financial Statements and the reported amounts of revenue and expenses during the reported periods. The Company bases its estimates on historical experience and on various other assumptions that management believes are reasonable under the circumstances, the results of which form the basis for making judgments about carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates. The notes to the Consolidated Financial Statements contained in the December 31, 2018 Consolidated Financial Statements include a discussion of the significant accounting policies and estimates used in the preparation of the Company's Consolidated Financial Statements. Except as noted below for the adoption of Accounting Standards Update ("ASU") 2016-02, Leases ("Topic 842"), there have been no material changes to the Company's significant accounting policies and estimates during the nine months ended September 30, 2019 . Leases The Company enters into operating lease contracts, as assessed at contract inception, primarily for real estate, data centers and equipment. On the Company's Consolidated Balance Sheets, Operating lease assets are included in Operating lease right-of-use assets and Operating lease liabilities are included in Other current liabilities and Long-term operating lease liabilities. At the lease commencement date, the Company records Operating lease liabilities based on the present value of the future lease payments. In determining the present value of future lease payments, the Company uses its incremental borrowing rate based on the information available at the commencement date. For real estate and data center contracts, the Company accounts for the lease and non-lease components as a single lease component. For certain equipment leases, the Company applies a portfolio approach to account for the right-of-use asset and operating lease liability. In assessing the lease term, the Company includes options to renew only when it is reasonably certain that it will be exercised; a determination which is at the sole discretion of the Company. Generally, for leases with an initial term of 12 months or less, the Company has elected to not record a right-of-use asset and lease liability. For equipment leases used in revenue generating activities, the Company will record a right-of-use asset and lease liability for leases with a term of 12 months or less. The Company records lease expense on a straight-line basis over the lease term beginning on the commencement date.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2019
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements Measurement of Credit Losses on Financial Instruments In June 2016, the Financial Accounting Standards Board issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The ASU introduces a new forward-looking approach, based on expected losses, to estimate credit losses on certain types of financial instruments, including trade receivables. The estimate of expected credit losses will require considerations of historical information, current information and reasonable and supportable forecasts. The ASU also expands the disclosure requirements to enable users of financial statements to understand the assumptions, models and methods for estimating expected credit losses. The ASU will be adopted on January 1, 2020. The Company has established a cross-functional implementation team to analyze the effect of the ASU. The analysis includes identifying pools of receivables, evaluating and assessing estimation methodologies, assessing policy elections, and evaluating its business processes and internal controls to meet the ASU’s accounting, reporting and disclosure requirements. The Company is currently evaluating the impact the ASU will have on its Consolidated Financial Statements. Accounting for Leases On January 1, 2019, the Company adopted and applied Topic 842 resulting in the recognition of right-of-use assets and additional lease liabilities of $ 81 million as of January 1, 2019, mainly related to operating leases for the Company's real estate portfolio. For additional details regarding the impact to the Company's Consolidated Balance Sheets from adopting this standard, see Note 9 (Leases) .

Acquisition

Acquisition	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Acquisition	Acquisition On February 1, 2019, the Company completed the acquisition of all issued and outstanding shares of Scalar Decisions Inc. ("Scalar"), a leading technology solutions provider in Canada, for a total final purchase price of $88 million of which $13 million is deferred to satisfy potential indemnity obligations and is expected to be paid in the first quarter of 2021. The financial results of Scalar have been included in the Company's Consolidated Financial Statements since the date of the acquisition. The financial results are included in the CDW Canada operating segment which is shown in an all other category ("Other") along with CDW UK. The purchase price allocation is preliminary and subject to revision as additional information about fair value of assets and liabilities becomes available. The preliminary purchase price allocation is as follows: (in millions) Acquisition-Date Fair Value Net assets acquired $ 5.7 Identified intangible assets (1) 20.3 Goodwill (2) 62.0 Total purchase price $ 88.0 (1) Net of a related deferred tax liability of $7 million . (2) Goodwill in the amount of $62 million was recognized in connection with the acquisition of Scalar, primarily attributed to cross selling opportunities and overall corporate synergies. The full amount of goodwill recognized is not deductible for income tax purposes in Canada.

Inventory Financing Agreements

Inventory Financing Agreements	9 Months Ended
	Sep. 30, 2019
Inventory Financing Agreements [Abstract]
Inventory Financing Agreements	Inventory Financing Agreements The Company has entered into agreements with certain financial intermediaries to facilitate the purchase of inventory from various suppliers under certain terms and conditions, as described below. These amounts are classified separately as Accounts payable-inventory financing on the Consolidated Balance Sheets. The Company does not incur any interest expense associated with these agreements as balances are paid when they are due. Amounts included in Accounts payable-inventory financing are as follows: (in millions) September 30, 2019 December 31, 2018 Revolving Loan inventory financing agreement (1) $ 382.1 $ 406.3 Other inventory financing agreements 29.6 23.0 Accounts payable-inventory financing $ 411.7 $ 429.3 (1) The Senior Secured Asset-Based Revolving Credit Facility includes an inventory floorplan sub-facility that enables the Company to maintain an inventory financing agreement with a financial intermediary to facilitate the purchase of inventory from certain vendors on more favorable terms than offered directly by the vendors.

Contract Liabilities and Perfor

Contract Liabilities and Performance Obligations	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Contract Liabilities and Performance Obligations	Contract Liabilities and Performance Obligations The Company's contract liabilities consist of payments received from customers, or such consideration that is contractually due, in advance of providing the product or performing services. The Company's contract liabilities are reported in a net position on a contract-by-contract basis at the end of each reporting period. As of September 30, 2019 and December 31, 2018 , the contract liability balance was $212 million and $178 million , respectively. During the nine months ended September 30, 2019 and 2018 , the Company recognized revenue of $117 million and $153 million , respectively, related to its contract liabilities. A contract's transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. The following table represents the total transaction price for the remaining performance obligations as of September 30, 2019 related to noncancelable contracts longer than 12 months in duration that is expected to be recognized over future periods. (in millions) Within 1 Year Years 1-2 Years 2-3 Thereafter Remaining performance obligations $ 40.2 $ 17.6 $ 5.1 $ 0.3

Financial Instruments

Financial Instruments	9 Months Ended
	Sep. 30, 2019
Financial Instruments [Abstract]
Financial Instruments	Financial Instruments The Company's indebtedness creates interest rate risk on its variable-rate debt. The Company uses derivative financial instruments to manage its exposure to interest rate risk. The Company does not hold or issue derivative financial instruments for trading or speculative purposes. The Company has interest rate cap agreements that entitle it to payments from the counterparty of the amount, if any, by which three-month London Interbank Offered Rate ("LIBOR") exceeds the strike rates of the caps during the agreement period in exchange for an upfront premium. During 2019 , the Company entered into interest rate cap agreements with a combined notional value of $1.2 billion resulting in premiums paid to the counterparties of $6 million . As of September 30, 2019 and December 31, 2018 , the Company had the following interest rate cap agreements for which the fair values are classified within Other assets on the Consolidated Balance Sheets: September 30, 2019 December 31, 2018 Notional Value (in millions) Effective Date Maturity Date Fair Value (in millions) Fair Value (in millions) $ 1,400.0 December 31, 2018 December 31, 2020 $ 0.1 $ 10.6 1,400.0 December 31, 2020 December 31, 2022 1.0 1.5 $ 1.1 $ 12.1 The fair values of the Company's interest rate cap agreements are classified as Level 2 in the fair value hierarchy. The valuation of the interest rate cap agreements is derived by using a discounted cash flow analysis on the expected cash receipts that would occur if variable interest rates rise above the strike rates of the caps. This analysis reflects the contractual terms of the interest rate cap agreements, including the period to maturity, and uses observable market-based inputs, including LIBOR curves and implied volatilities. The Company also incorporates insignificant credit valuation adjustments to appropriately reflect the respective counterparty's nonperformance risk in the fair value measurements. The counterparty credit spreads are based on publicly available credit information obtained from a third-party credit data provider. For additional details, see Note 7 (Long-Term Debt) . The interest rate cap agreements are designated as cash flow hedges. The changes in the fair value of derivatives that qualify as cash flow hedges are recorded in Accumulated other comprehensive loss and are subsequently reclassified into Interest expense in the period when the hedged forecasted transaction affects earnings. The Company recorded an insignificant loss and a loss of $13 million , net of tax, into Accumulated other comprehensive loss for the three and nine months ended September 30, 2019 , respectively. The Company recorded a loss of $1 million and a gain of $3 million , net of tax, into Accumulated other comprehensive loss for the three and nine months ended September 30, 2018 , respectively. During the three and nine months ended September 30, 2019 , the Company reclassified an insignificant amount and $2 million , respectively, from Accumulated other comprehensive loss to earnings within Interest expense, net on the Consolidated Statement of Operations. During the three and nine months ended September 30, 2018 , the Company reclassified $1 million and $3 million , respectively, from Accumulated other comprehensive loss to earnings within Interest expense, net on the Consolidated Statement of Operations. The Company expects to reclassify $7 million from Accumulated other comprehensive loss to earnings within Interest expense, net during the next 12 months.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt As of September 30, 2019 As of December 31, 2018 (dollars in millions) Maturity Interest Rate Amount Interest Rate Amount Credit Facilities CDW UK revolving credit facility (1) July 2021 — % $ — — % $ — Senior secured asset-based revolving credit facility March 2022 3.31 % 26.0 — % — Total credit facilities 26.0 — Term Loans CDW UK term loan (1) August 2021 2.16 % 56.5 2.29 % 65.0 Senior secured term loan facility (2) August 2023 3.80 % 1,442.0 4.10 % 1,453.2 Total term loans 1,498.5 1,518.2 Unsecured Senior Notes Senior notes due 2023 ("2023 Senior Notes") September 2023 — % — 5.00 % 525.0 Senior notes due 2024 ("2024 Senior Notes") December 2024 5.50 % 575.0 5.50 % 575.0 Senior notes due 2025 ("2025 Senior Notes") September 2025 5.00 % 600.0 5.00 % 600.0 Senior notes due 2028 ("2028 Senior Notes") April 2028 4.25 % 600.0 — % — Total unsecured senior notes 1,775.0 1,700.0 Other long-term obligations 4.4 8.3 Unamortized deferred financing fees (19.5 ) (17.9 ) Current maturities of long-term debt (25.4 ) (25.3 ) Total long-term debt $ 3,259.0 $ 3,183.3 (1) British pound-denominated debt facilities. (2) See Note 14 (Subsequent Events). As of September 30, 2019 , the Company is in compliance with the covenants under the various credit agreements and indentures. Credit Facilities The Company has a variable rate CDW UK revolving credit facility that is denominated in British pounds. As of September 30, 2019 , the Company could have borrowed up to an additional £ 50 million ($ 61 million at September 30, 2019 ) under the CDW UK revolving credit facility. The Company also has a variable rate senior secured asset-based revolving credit facility (the "Revolving Loan") that is denominated in US dollars. The Revolving Loan is used by the Company for borrowings, issuances of letters of credit and floorplan financing. As of September 30, 2019 , the Revolving Loan had less than $ 1 million of undrawn letters of credit, $ 356 million reserved for the floorplan sub-facility and a borrowing base of $ 2.2 billion , which is based on the amount of eligible inventory and accounts receivable balances as of August 31, 2019 . As of September 30, 2019 , the Company could have borrowed up to an additional $1.1 billion under the Revolving Loan. The Revolving Loan is collateralized by a first priority interest in inventory (excluding inventory to the extent collateralized under the inventory financing arrangements as described in Note 4 (Inventory Financing Agreements) ), deposits and accounts receivable, and by a second priority interest in substantially all other US assets. Term Loans The CDW UK term loan has a variable interest rate. The Company is required to make annual principal installments of £ 5 million ($ 6 million at September 30, 2019 ), with the remaining principal amount due at the maturity date. The CDW UK term loan agreement imposes restrictions on CDW UK's ability to transfer funds to the Company through the payment of dividends, repayment of intercompany loans, advances or subordinated debt that require, among other things, the maintenance of a minimum net leverage ratio. As of September 30, 2019 , the amount of restricted payment capacity under the CDW UK term loan was £ 134 million ($ 165 million at September 30, 2019 ). The senior secured term loan facility (the "Term Loan") has a variable interest rate, which has effectively been capped through the use of interest rate caps (see Note 6 (Financial Instruments) ). The interest rate disclosed in the table above represents the variable interest rates in effect for September 30, 2019 and December 31, 2018 , respectively. The Company is required to pay quarterly principal installments of $ 4 million with the remaining principal amount due at the maturity date. As of September 30, 2019 , the amount of CDW's restricted payment capacity under the Term Loan was $1.7 billion . The Term Loan is collateralized by a second priority interest in substantially all inventory (excluding inventory to the extent collateralized under the inventory financing arrangements as described in Note 4 (Inventory Financing Agreements) , deposits and accounts receivable, and by a first priority interest in substantially all other US assets. Unsecured Senior Notes The 2024 Senior Notes and 2025 Senior Notes have a fixed interest rate, for which interest is paid semi-annually. On September 26, 2019 , the Company completed the issuance of $600 million aggregate principal amount of 4.25% Senior Notes due 2028 at par. The 2028 Senior Notes will mature on April 1, 2028 and bear interest at a rate of 4.25% per annum, payable semi-annually on April 1 and October 1 of each year, commencing on April 1, 2020. The net proceeds from the issuance of the 2028 Senior Notes were primarily used to redeem all of the remaining $525 million aggregate principal amount of the 2023 Senior Notes at a redemption price of 102.5% of the principal amount redeemed, plus accrued and unpaid interest to the date of redemption, and to pay fees and expenses related to the issuance and redemption. The redemption date was October 12, 2019. On the same date, the indenture governing the 2023 Senior Notes was satisfied and discharged. Fair Value The fair values of the Senior Notes were estimated using quoted market prices for identical liabilities that are traded in over-the-counter secondary markets that are not considered active. The fair value of the Term Loan was estimated using dealer quotes for identical liabilities in markets that are not considered active. The Senior Notes, Term Loan and CDW UK term loan are classified as Level 2 within the fair value hierarchy. The carrying value of the Revolving Loan and CDW UK revolving credit facility approximate fair value if there are outstanding borrowings. The approximate fair values and related carrying values of the Company's long-term debt, including current maturities and excluding unamortized discount and unamortized deferred financing fees, are as follows: (in millions) September 30, 2019 December 31, 2018 Fair value $ 3,412.3 $ 3,145.8 Carrying value 3,303.9 3,226.5

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense was $59 million for the three months ended September 30, 2019 , compared to $55 million for the same period of the prior year. The effective tax rate, expressed by calculating the income tax expense as a percentage of Income before income taxes, was 22.7% and 22.9% for the three months ended September 30, 2019 and 2018 , respectively, and differed from the US federal statutory rate of 21.0% primarily due to state income taxes partially offset by excess tax benefits on equity-based compensation. Income tax expense was $163 million for the nine months ended September 30, 2019 , compared to $150 million for the same period of the prior year. The effective tax rate was 22.8% and 23.7% for the nine months ended September 30, 2019 and 2018

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	Leases The Company has operating leases primarily for real estate, data centers and equipment. Lease terms range from 1 year to 17 years . Supplemental Consolidated Balance Sheet information related to the Company's operating leases is as follows: (in millions) Classification on the Consolidated Balance Sheets September 30, 2019 Assets Operating lease right-of-use assets $ 84.2 Liabilities Current Accrued expenses and other current liabilities - Other $ 30.6 Long-term Long-term operating lease liabilities 81.7 Total lease liabilities $ 112.3 Lease term and discount rate September 30, 2019 Weighted average remaining lease term (years) 5.8 Weighted average discount rate 4.53 % The components of operating lease expense are as follows: (in millions) Financial statement line item Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Cost of sales $ 43.9 $ 57.7 Selling and administrative expenses 7.0 21.9 Total lease cost $ 50.9 $ 79.6 Maturities of operating lease liabilities are as follows: (in millions) September 30, 2019 Remainder of 2019 $ 8.2 2020 31.5 2021 22.2 2022 15.0 2023 11.7 Thereafter 38.3 Total lease payments $ 126.9 Less: Interest (14.6 ) Present value of lease liabilities $ 112.3 Supplemental cash flow information related to operating leases is as follows: (in millions) Nine Months Ended September 30, 2019 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 79.5 Right-of-use assets obtained in exchange for lease obligations Operating leases $ 56.0 As of September 30, 2019 , the Company has an additional operating lease commitment that has not yet commenced of $99 million . This operating lease is expected to commence in 2019 with a lease term of 17 years .

Earnings per Share

Earnings per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings per Share	Earnings Per Share The numerator for both basic and diluted earnings per share is Net income. The denominator for basic earnings per share is the weighted-average shares outstanding during the period. A reconciliation of basic weighted-average shares outstanding to diluted weighted-average shares outstanding is as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2019 2018 2019 2018 Basic weighted-average shares outstanding 144.5 150.9 145.7 151.6 Effect of dilutive securities (1) 2.7 2.8 2.5 2.5 Diluted weighted-average shares outstanding (2) 147.2 153.7 148.2 154.1 (1) The dilutive effect of outstanding stock options, restricted stock units, restricted stock, performance share units and Coworker Stock Purchase Plan units is reflected in the diluted weighted-average shares outstanding using the treasury stock method. (2) There were fewer than 0.1 million potential common shares excluded from diluted weighted-average shares outstanding for both the three and nine months ended September 30, 2019 and 2018 as their inclusion would have had an anti-dilutive effect.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company is party to various legal proceedings that arise in the ordinary course of its business, which include commercial, intellectual property, employment, tort and other litigation matters. The Company is also subject to audit by federal, state, international, national, provincial and local authorities, and by various partners, group purchasing organizations and customers, including government agencies, relating to purchases and sales under various contracts. In addition, the Company is subject to indemnification claims under various contracts. From time to time, certain customers of the Company file voluntary petitions for reorganization or liquidation under the US bankruptcy laws or similar laws of the jurisdictions for the Company's business activities outside of the US. In such cases, certain pre-petition payments received by the Company could be considered preference items and subject to return to the bankruptcy administrator. As of September 30, 2019 , the Company does not believe that there is a reasonable possibility that any material loss exceeding the amounts already recognized for these proceedings and matters, if any, has been incurred. However, the ultimate resolutions of these proceedings and matters are inherently unpredictable. As such, the Company's financial condition and results of operations could be adversely affected in any particular period by the unfavorable resolution of one or more of these proceedings or matters.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment Information	Segment Information The Company has three reportable segments: Corporate, which is comprised primarily of US private sector business customers with more than 250 employees, Small Business, which primarily serves US private sector business customers with up to 250 employees, and Public, which is comprised of government agencies and education and healthcare institutions in the US. The Company has two other operating segments: CDW UK and CDW Canada, both of which do not meet the reportable segment quantitative thresholds and, accordingly, are included in an all other category ("Other"). Headquarters function costs that are not allocated to the segments are included under the heading of "Headquarters" in the tables below. During the first quarter of 2019, the Company evaluated its methodology for allocating certain depreciation and amortization expenses to each of its segments. The evaluation resulted in a revision to the allocation of depreciation and amortization expenses from Headquarters to the Company’s reportable segments, effective January 1, 2019. The prior period results have been recast to reflect these changes and present comparable information. Information about the Company's segments is as follows: (in millions) Corporate Small Business Public Other Headquarters Total Three Months Ended September 30, 2019 Net sales $ 1,913.5 $ 386.2 $ 2,100.9 $ 507.1 $ — $ 4,907.7 Operating income (loss) 138.9 27.2 168.4 21.9 (35.8 ) 320.6 Depreciation and amortization expense (21.7 ) (5.6 ) (15.0 ) (7.9 ) (18.0 ) (68.2 ) Three Months Ended September 30, 2018 Net sales $ 1,706.5 $ 340.0 $ 1,875.1 $ 451.6 $ — $ 4,373.2 Operating income (loss) 125.7 23.8 136.6 19.2 (30.5 ) 274.8 Depreciation and amortization expense (21.8 ) (5.5 ) (12.9 ) (7.3 ) (18.3 ) (65.8 ) (in millions) Corporate Small Business Public Other Headquarters Total Nine Months Ended September 30, 2019 Net sales $ 5,533.6 $ 1,119.2 $ 5,271.7 $ 1,571.0 $ — $ 13,495.5 Operating income (loss) 430.8 78.2 373.9 66.6 (99.7 ) 849.8 Depreciation and amortization expense (64.8 ) (16.8 ) (41.4 ) (23.1 ) (51.4 ) (197.5 ) Nine Months Ended September 30, 2018 Net sales $ 5,006.1 $ 997.1 $ 4,740.5 $ 1,422.0 $ — $ 12,165.7 Operating income (loss) 388.3 70.0 318.3 60.7 (92.9 ) 744.4 Depreciation and amortization expense (66.8 ) (16.6 ) (38.4 ) (25.1 ) (51.8 ) (198.7 ) Geographic Areas and Revenue Mix Three Months Ended September 30, 2019 (in millions) Corporate Small Business Public Other Total Geography (1) United States $ 1,910.9 $ 386.2 $ 2,100.9 $ 7.6 $ 4,405.6 Rest of World 2.6 — — 499.5 502.1 Total Net sales 1,913.5 386.2 2,100.9 507.1 4,907.7 Major Product and Services Hardware 1,528.0 326.6 1,711.3 358.3 3,924.2 Software 269.1 47.6 324.4 66.1 707.2 Services 97.9 6.7 59.0 80.2 243.8 Other (2) 18.5 5.3 6.2 2.5 32.5 Total Net sales 1,913.5 386.2 2,100.9 507.1 4,907.7 Sales by Channel Corporate 1,913.5 — — — 1,913.5 Small Business — 386.2 — — 386.2 Government — — 793.4 — 793.4 Education — — 807.0 — 807.0 Healthcare — — 500.5 — 500.5 Other — — — 507.1 507.1 Total Net sales 1,913.5 386.2 2,100.9 507.1 4,907.7 Timing of Revenue Recognition Transferred at a point in time where CDW is principal 1,743.4 364.0 1,939.3 443.8 4,490.5 Transferred at a point in time where CDW is agent 111.0 19.6 79.6 15.5 225.7 Transferred over time where CDW is principal 59.1 2.6 82.0 47.8 191.5 Total Net sales $ 1,913.5 $ 386.2 $ 2,100.9 $ 507.1 $ 4,907.7 (1) Net sales by geography is generally based on the ship-to address with the exception of certain services that may be performed at, or on behalf of, multiple locations. Such service arrangements are categorized based on the bill-to address. (2) Includes items such as delivery charges to customers. Three Months Ended September 30, 2018 (in millions) Corporate Small Business Public Other Total Geography (1) United States $ 1,704.1 $ 340.0 $ 1,875.1 $ 6.8 $ 3,926.0 Rest of World 2.4 — — 444.8 447.2 Total Net sales 1,706.5 340.0 1,875.1 451.6 4,373.2 Major Product and Services Hardware 1,379.5 284.0 1,530.8 363.6 3,557.9 Software 227.5 44.3 291.0 45.6 608.4 Services 83.1 6.6 48.8 40.5 179.0 Other (2) 16.4 5.1 4.5 1.9 27.9 Total Net sales 1,706.5 340.0 1,875.1 451.6 4,373.2 Sales by Channel Corporate 1,706.5 — — — 1,706.5 Small Business — 340.0 — — 340.0 Government — — 639.3 — 639.3 Education — — 793.1 — 793.1 Healthcare — — 442.7 — 442.7 Other — — — 451.6 451.6 Total Net sales 1,706.5 340.0 1,875.1 451.6 4,373.2 Timing of Revenue Recognition Transferred at a point in time where CDW is principal 1,571.6 321.0 1,764.6 402.8 4,060.0 Transferred at a point in time where CDW is agent 85.7 16.9 64.3 12.3 179.2 Transferred over time where CDW is principal 49.2 2.1 46.2 36.5 134.0 Total Net sales $ 1,706.5 $ 340.0 $ 1,875.1 $ 451.6 $ 4,373.2 (1) Net sales by geography is generally based on the ship-to address with the exception of certain services that may be performed at, or on behalf of, multiple locations. Such service arrangements are categorized based on the bill-to address. (2) Includes items such as delivery charges to customers. Nine Months Ended September 30, 2019 (in millions) Corporate Small Business Public Other Total Geography (1) United States $ 5,525.5 $ 1,119.2 $ 5,271.7 $ 24.8 $ 11,941.2 Rest of World 8.1 — — 1,546.2 1,554.3 Total Net sales 5,533.6 1,119.2 5,271.7 1,571.0 13,495.5 Major Product and Services Hardware 4,411.6 937.5 4,297.6 1,143.0 10,789.7 Software 784.8 145.0 808.0 213.3 1,951.1 Services 284.0 20.8 150.8 206.3 661.9 Other (2) 53.2 15.9 15.3 8.4 92.8 Total Net sales 5,533.6 1,119.2 5,271.7 1,571.0 13,495.5 Sales by Channel Corporate 5,533.6 — — — 5,533.6 Small Business — 1,119.2 — — 1,119.2 Government — — 1,860.2 — 1,860.2 Education — — 1,981.0 — 1,981.0 Healthcare — — 1,430.5 — 1,430.5 Other — — — 1,571.0 1,571.0 Total Net sales 5,533.6 1,119.2 5,271.7 1,571.0 13,495.5 Timing of Revenue Recognition Transferred at a point in time where CDW is principal 5,033.4 1,054.7 4,908.0 1,383.7 12,379.8 Transferred at a point in time where CDW is agent 333.7 59.4 190.9 42.0 626.0 Transferred over time where CDW is principal 166.5 5.1 172.8 145.3 489.7 Total Net sales $ 5,533.6 $ 1,119.2 $ 5,271.7 $ 1,571.0 $ 13,495.5 (1) Net sales by geography is generally based on the ship-to address with the exception of certain services that may be performed at, or on behalf of, multiple locations. Such service arrangements are categorized based on the bill-to address. (2) Includes items such as delivery charges to customers. Nine Months Ended September 30, 2018 (in millions) Corporate Small Business Public Other Total Geography (1) United States $ 4,999.9 $ 997.1 $ 4,740.5 $ 24.0 $ 10,761.5 Rest of World 6.2 — — 1,398.0 1,404.2 Total Net sales 5,006.1 997.1 4,740.5 1,422.0 12,165.7 Major Product and Services Hardware 4,013.4 829.4 3,876.7 1,136.9 9,856.4 Software 699.6 131.2 730.5 154.0 1,715.3 Services 242.3 20.6 120.5 124.8 508.2 Other (2) 50.8 15.9 12.8 6.3 85.8 Total Net sales 5,006.1 997.1 4,740.5 1,422.0 12,165.7 Sales by Channel Corporate 5,006.1 — — — 5,006.1 Small Business — 997.1 — — 997.1 Government — — 1,551.3 — 1,551.3 Education — — 1,902.4 — 1,902.4 Healthcare — — 1,286.8 — 1,286.8 Other — — — 1,422.0 1,422.0 Total Net sales 5,006.1 997.1 4,740.5 1,422.0 12,165.7 Timing of Revenue Recognition Transferred at a point in time where CDW is principal 4,581.3 940.0 4,445.8 1,277.4 11,244.5 Transferred at a point in time where CDW is agent 279.9 50.5 160.7 37.1 528.2 Transferred over time where CDW is principal 144.9 6.6 134.0 107.5 393.0 Total Net sales $ 5,006.1 $ 997.1 $ 4,740.5 $ 1,422.0 $ 12,165.7 (1) Net sales by geography is generally based on the ship-to address with the exception of certain services that may be performed at, or on behalf of, multiple locations. Such service arrangements are categorized based on the bill-to address. (2) Includes items such as delivery charges to customers. The following table presents Net sales by major category for the three and nine months ended September 30, 2019 and 2018 . Categories are based upon internal classifications. Three Months Ended September 30, 2019 2018 Dollars in Percentage Dollars in Percentage Notebooks/Mobile Devices $ 1,325.6 27.0 % $ 1,124.8 25.7 % Netcomm Products 567.3 11.6 582.4 13.3 Desktops 448.4 9.1 349.0 8.0 Video 353.3 7.2 320.5 7.3 Enterprise and Data Storage (Including Drives) 283.6 5.8 297.4 6.8 Other Hardware 946.0 19.3 883.8 20.3 Total Hardware 3,924.2 80.0 3,557.9 81.4 Software (1) 707.2 14.3 608.4 13.9 Services (1) 243.8 5.0 179.0 4.1 Other (2) 32.5 0.7 27.9 0.6 Total Net sales $ 4,907.7 100.0 % $ 4,373.2 100.0 % Nine Months Ended September 30, 2019 2018 Dollars in Percentage Dollars in Percentage Notebooks/Mobile Devices $ 3,537.5 26.2 % $ 3,069.4 25.2 % Netcomm Products 1,641.9 12.2 1,568.5 12.9 Desktops 1,183.6 8.8 1,013.2 8.3 Video 972.7 7.2 904.4 7.4 Enterprise and Data Storage (Including Drives) 849.2 6.3 816.2 6.7 Other Hardware 2,604.8 19.3 2,484.7 20.5 Total Hardware 10,789.7 80.0 9,856.4 81.0 Software (1) 1,951.1 14.4 1,715.3 14.1 Services (1) 661.9 4.9 508.2 4.2 Other (2) 92.8 0.7 85.8 0.7 Total Net sales $ 13,495.5 100.0 % $ 12,165.7 100.0 % (1) Certain software and services revenues are recorded on a net basis for accounting purposes. As a result, the category percentage of net revenues is not representative of the category percentage of gross profits. (2) Includes items such as delivery charges to customers.

Supplemental Guarantor Informat

Supplemental Guarantor Information	9 Months Ended
	Sep. 30, 2019
Supplemental Guarantor Information [Abstract]
Supplemental Guarantor Information	Supplemental Guarantor Information The Senior Notes are guaranteed by Parent and each of CDW LLC's direct and indirect, 100% owned, domestic subsidiaries (the "Guarantor Subsidiaries"). All guarantees by Parent and the Guarantor Subsidiaries are and were joint and several, and full and unconditional; provided that guarantees by the Guarantor Subsidiaries are subject to certain customary release provisions contained in the indentures governing the Senior Notes. CDW LLC's 100% owned foreign subsidiaries, CDW International Holdings Limited, which is comprised of CDW UK and CDW Canada (together the "Non-Guarantor Subsidiaries"), do not guarantee the Senior Notes. CDW LLC and CDW Finance Corporation, as co-issuers, are 100% owned by Parent and each of the Guarantor Subsidiaries and the Non-Guarantor Subsidiaries are, directly or indirectly, 100% owned by CDW LLC. The following tables set forth Condensed Consolidating Balance Sheets as of September 30, 2019 and December 31, 2018 , Consolidating Statements of Operations for the three and nine months ended September 30, 2019 and 2018 , Condensed Consolidating Statements of Comprehensive Income for the three and nine months ended September 30, 2019 and 2018 , and Condensed Consolidating Statements of Cash Flows for the nine months ended September 30, 2019 and 2018 , in accordance with Rule 3-10 of Regulation S-X. The consolidating financial information includes the accounts of CDW Corporation (the "Parent Guarantor"), which has no independent assets or operations, the accounts of CDW LLC (the "Subsidiary Issuer"), the combined accounts of the Guarantor Subsidiaries, the combined accounts of the Non-Guarantor Subsidiaries, and the accounts of CDW Finance Corporation (the "Co-Issuer") for the periods indicated. The information is prepared on the same basis as the Company's Consolidated Financial Statements. Condensed Consolidating Balance Sheet September 30, 2019 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Assets Current assets: Cash and cash equivalents $ — $ 124.1 $ — $ 78.5 $ — $ (35.7 ) $ 166.9 Accounts receivable, net — — 2,539.1 360.4 — — 2,899.5 Merchandise inventory — — 525.2 78.4 — — 603.6 Miscellaneous receivables — 103.1 300.6 28.5 — — 432.2 Prepaid expenses and other — 22.2 122.6 48.3 — — 193.1 Total current assets — 249.4 3,487.5 594.1 — (35.7 ) 4,295.3 Operating lease right-of-use assets — 23.2 33.1 27.9 — — 84.2 Property and equipment, net — 75.8 68.4 26.9 — — 171.1 Goodwill — 751.8 1,437.9 326.2 — — 2,515.9 Other intangible assets, net — 243.1 206.2 166.8 — — 616.1 Other assets 1.0 27.0 2.4 172.1 — (182.0 ) 20.5 Investment in and advances to subsidiaries 934.1 3,189.6 — — — (4,123.7 ) — Total Assets $ 935.1 $ 4,559.9 $ 5,235.5 $ 1,314.0 $ — $ (4,341.4 ) $ 7,703.1 Liabilities and Stockholders' Equity Current liabilities: Accounts payable-trade $ — $ 26.2 $ 1,701.9 $ 207.6 $ — $ (35.7 ) $ 1,900.0 Accounts payable-inventory financing — 0.1 382.0 29.6 — — 411.7 Current maturities of long-term debt — 14.9 4.2 6.3 — — 25.4 Contract liabilities — — 127.1 85.0 — — 212.1 Accrued expenses and other current liabilities — 256.0 352.0 83.8 — — 691.8 Total current liabilities — 297.2 2,567.2 412.3 — (35.7 ) 3,241.0 Long-term liabilities: Debt — 3,209.1 — 49.9 — — 3,259.0 Deferred income taxes — 51.7 32.0 28.7 — (1.1 ) 111.3 Operating lease liabilities — 33.0 25.2 23.5 — — 81.7 Other liabilities — 34.8 0.9 220.2 — (180.9 ) 75.0 Total long-term liabilities — 3,328.6 58.1 322.3 — (182.0 ) 3,527.0 Total stockholders' equity 935.1 934.1 2,610.2 579.4 — (4,123.7 ) 935.1 Total Liabilities and Stockholders' Equity $ 935.1 $ 4,559.9 $ 5,235.5 $ 1,314.0 $ — $ (4,341.4 ) $ 7,703.1 Condensed Consolidating Balance Sheet December 31, 2018 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Assets Current assets: Cash and cash equivalents $ — $ 176.0 $ — $ 46.7 $ — $ (16.9 ) $ 205.8 Accounts receivable, net — — 2,331.2 340.0 — — 2,671.2 Merchandise inventory — — 387.4 66.9 — — 454.3 Miscellaneous receivables — 110.6 187.7 18.1 — — 316.4 Prepaid expenses and other — 17.1 93.8 38.2 — — 149.1 Total current assets — 303.7 3,000.1 509.9 — (16.9 ) 3,796.8 Property and equipment, net — 82.3 52.0 21.8 — — 156.1 Goodwill — 751.8 1,437.8 273.2 — — 2,462.8 Other intangible assets, net — 252.5 300.0 159.7 — — 712.2 Other assets 1.4 49.8 9.6 140.2 — (161.2 ) 39.8 Investment in and advances to subsidiaries 973.8 3,028.9 — — — (4,002.7 ) — Total Assets $ 975.2 $ 4,469.0 $ 4,799.5 $ 1,104.8 $ — $ (4,180.8 ) $ 7,167.7 Liabilities and Stockholders' Equity Current liabilities: Accounts payable-trade $ — $ 39.2 $ 1,387.9 $ 166.9 $ — $ (16.9 ) $ 1,577.1 Accounts payable-inventory financing — 0.2 406.1 23.0 — — 429.3 Current maturities of long-term debt — 14.9 4.0 6.4 — — 25.3 Contract liabilities — — 95.6 82.7 — — 178.3 Accrued expenses and other current liabilities — 217.6 306.7 68.8 — — 593.1 Total current liabilities — 271.9 2,200.3 347.8 — (16.9 ) 2,803.1 Long-term liabilities: Debt — 3,121.3 4.3 57.7 — — 3,183.3 Deferred income taxes — 55.9 60.5 26.9 — (1.4 ) 141.9 Other liabilities — 46.1 5.7 172.2 — (159.8 ) 64.2 Total long-term liabilities — 3,223.3 70.5 256.8 — (161.2 ) 3,389.4 Total stockholders' equity 975.2 973.8 2,528.7 500.2 — (4,002.7 ) 975.2 Total Liabilities and Stockholders' Equity $ 975.2 $ 4,469.0 $ 4,799.5 $ 1,104.8 $ — $ (4,180.8 ) $ 7,167.7 Consolidating Statement of Operations Three Months Ended September 30, 2019 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Net sales $ — $ — $ 4,400.6 $ 507.1 $ — $ — $ 4,907.7 Cost of sales — — 3,671.5 419.7 — — 4,091.2 Gross profit — — 729.1 87.4 — — 816.5 Selling and administrative expenses — 35.8 347.4 61.7 — — 444.9 Advertising expense — — 47.2 3.8 — — 51.0 Operating income (loss) — (35.8 ) 334.5 21.9 — — 320.6 Interest (expense) income, net — (42.0 ) 0.1 (0.4 ) — — (42.3 ) Other income, net — (16.1 ) — (1.3 ) — — (17.4 ) Income (loss) before income taxes — (93.9 ) 334.6 20.2 — — 260.9 Income tax (expense) benefit (0.1 ) 30.3 (87.9 ) (1.5 ) — — (59.2 ) Income (loss) before equity in earnings of subsidiaries (0.1 ) (63.6 ) 246.7 18.7 — — 201.7 Equity in earnings of subsidiaries 201.8 265.4 — — — (467.2 ) — Net income $ 201.7 $ 201.8 $ 246.7 $ 18.7 $ — $ (467.2 ) $ 201.7 Consolidating Statement of Operations Three Months Ended September 30, 2018 (in millions) Parent Subsidiary Guarantor Non-Guarantor Co-Issuer Consolidating Consolidated Net sales $ — $ — $ 3,921.6 $ 451.6 $ — $ — $ 4,373.2 Cost of sales — — 3,286.6 373.0 — — 3,659.6 Gross profit — — 635.0 78.6 — — 713.6 Selling and administrative expenses — 33.7 299.8 57.2 — — 390.7 Advertising expense — — 45.9 2.2 — — 48.1 Operating income (loss) — (33.7 ) 289.3 19.2 — — 274.8 Interest (expense) income, net — (36.1 ) 0.9 (1.4 ) — — (36.6 ) Other income, net — — 0.1 0.1 — — 0.2 Income (loss) before income taxes — (69.8 ) 290.3 17.9 — — 238.4 Income tax (expense) benefit (0.1 ) 20.5 (75.3 ) 0.2 — — (54.7 ) Income (loss) before equity in earnings of subsidiaries (0.1 ) (49.3 ) 215.0 18.1 — — 183.7 Equity in earnings of subsidiaries 183.8 233.1 — — — (416.9 ) — Net income $ 183.7 $ 183.8 $ 215.0 $ 18.1 $ — $ (416.9 ) $ 183.7 Consolidating Statement of Operations Nine Months Ended September 30, 2019 (in millions) Parent Subsidiary Guarantor Non-Guarantor Co-Issuer Consolidating Consolidated Net sales $ — $ — $ 11,924.5 $ 1,571.0 $ — $ — $ 13,495.5 Cost of sales — — 9,926.3 1,306.8 — — 11,233.1 Gross profit — — 1,998.2 264.2 — — 2,262.4 Selling and administrative expenses — 99.7 980.6 189.0 — — 1,269.3 Advertising expense — — 134.7 8.6 — — 143.3 Operating income (loss) — (99.7 ) 882.9 66.6 — — 849.8 Interest (expense) income, net — (120.2 ) 0.3 (1.2 ) — — (121.1 ) Other (expense) income, net — (16.1 ) 2.1 (1.0 ) — — (15.0 ) Income (loss) before income taxes — (236.0 ) 885.3 64.4 — — 713.7 Income tax (expense) benefit (0.3 ) 75.2 (229.2 ) (8.2 ) — — (162.5 ) Income (loss) before equity in earnings of subsidiaries (0.3 ) (160.8 ) 656.1 56.2 — — 551.2 Equity in earnings of subsidiaries 551.5 712.3 — — — (1,263.8 ) — Net income $ 551.2 $ 551.5 $ 656.1 $ 56.2 $ — $ (1,263.8 ) $ 551.2 Consolidating Statement of Operations Nine Months Ended September 30, 2018 (in millions) Parent Subsidiary Guarantor Non-Guarantor Co-Issuer Consolidating Consolidated Net sales $ — $ — $ 10,743.7 $ 1,422.0 $ — $ — $ 12,165.7 Cost of sales — — 8,966.6 1,186.0 — — 10,152.6 Gross profit — — 1,777.1 236.0 — — 2,013.1 Selling and administrative expenses — 103.3 861.8 169.7 — — 1,134.8 Advertising expense — — 128.3 5.6 — — 133.9 Operating income (loss) — (103.3 ) 787.0 60.7 — — 744.4 Interest (expense) income, net — (109.9 ) 2.8 (4.4 ) — — (111.5 ) Other income, net — — 0.6 0.4 — — 1.0 Income (loss) before income taxes — (213.2 ) 790.4 56.7 — — 633.9 Income tax (expense) benefit (0.3 ) 61.5 (202.6 ) (8.8 ) — — (150.2 ) Income (loss) before equity in earnings of subsidiaries (0.3 ) (151.7 ) 587.8 47.9 — — 483.7 Equity in earnings of subsidiaries 484.0 635.7 — — — (1,119.7 ) — Net income $ 483.7 $ 484.0 $ 587.8 $ 47.9 $ — $ (1,119.7 ) $ 483.7 Condensed Consolidating Statement of Comprehensive Income Three Months Ended September 30, 2019 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Comprehensive income $ 187.0 $ 187.1 $ 246.7 $ 4.1 $ — $ (437.9 ) $ 187.0 Condensed Consolidating Statement of Comprehensive Income Three Months Ended September 30, 2018 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Comprehensive income $ 180.6 $ 180.7 $ 215.0 $ 14.9 $ — $ (410.6 ) $ 180.6 Condensed Consolidating Statement of Comprehensive Income Nine Months Ended September 30, 2019 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Comprehensive income $ 527.7 $ 528.0 $ 656.1 $ 43.5 $ — $ (1,227.6 ) $ 527.7 Condensed Consolidating Statement of Comprehensive Income Nine Months Ended September 30, 2018 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Comprehensive income $ 471.4 $ 471.7 $ 587.8 $ 30.0 $ — $ (1,089.5 ) $ 471.4 Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2019 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Net cash provided by (used in) operating activities $ — $ (6.3 ) $ 620.6 $ 95.4 $ — $ (27.4 ) $ 682.3 Cash flows used in investing activities: Capital expenditures — (46.4 ) (19.5 ) (9.1 ) — — (75.0 ) Acquisition of business, net of cash acquired — — — (75.0 ) — — (75.0 ) Net cash used in investing activities — (46.4 ) (19.5 ) (84.1 ) — — (150.0 ) Cash flows (used in) provided by financing activities: Proceeds from borrowings under revolving credit facility — 1,860.5 — — — — 1,860.5 Repayments of borrowings under revolving credit facility — (1,834.5 ) — — — — (1,834.5 ) Repayments of long-term debt — (11.0 ) — (8.7 ) — — (19.7 ) Proceeds from issuance of long-term debt — 600.0 — — — — 600.0 Payments to extinguish long-term debt — (538.1 ) — — — — (538.1 ) Net change in accounts payable-inventory financing — — (24.2 ) 6.8 — — (17.4 ) Repurchases of common stock (493.3 ) — — — — — (493.3 ) Payment of incentive compensation plan withholding taxes (21.3 ) — — — — — (21.3 ) Dividend payments (128.9 ) — — — — — (128.9 ) Capital contributions — (76.0 ) — 76.0 — — — Other — 28.8 (4.4 ) (0.2 ) — — 24.2 Distributions and advances from (to) affiliates 643.5 (28.9 ) (572.5 ) (50.7 ) — 8.6 — Net cash (used in) provided by financing activities — 0.8 (601.1 ) 23.2 — 8.6 (568.5 ) Effect of exchange rate changes on cash and cash equivalents — — — (2.7 ) — — (2.7 ) Net (decrease) increase in cash and cash equivalents — (51.9 ) — 31.8 — (18.8 ) (38.9 ) Cash and cash equivalents—beginning of period — 176.0 — 46.7 — (16.9 ) 205.8 Cash and cash equivalents—end of period $ — $ 124.1 $ — $ 78.5 $ — $ (35.7 ) $ 166.9 Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2018 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Net cash provided by (used in) operating activities $ — $ (78.9 ) $ 608.4 $ 80.2 $ — $ (7.4 ) $ 602.3 Cash flows used in investing activities: Capital expenditures — (40.9 ) (3.5 ) (9.0 ) — — (53.4 ) Net cash used in investing activities — (40.9 ) (3.5 ) (9.0 ) — — (53.4 ) Cash flows (used in) provided by financing activities: Proceeds from borrowings under revolving credit facility — 640.0 — 48.9 — — 688.9 Repayments of borrowings under revolving credit facility — (640.0 ) — (41.9 ) — — (681.9 ) Repayments of long-term debt — (11.2 ) — (7.0 ) — — (18.2 ) Net change in accounts payable-inventory financing — (0.8 ) (85.8 ) (3.5 ) — — (90.1 ) Repurchases of common stock (232.5 ) — — — — — (232.5 ) Payment of incentive compensation plan withholding taxes (27.1 ) — — — — — (27.1 ) Dividend payments (95.5 ) — — — — — (95.5 ) Repayment of intercompany loan — — 47.5 (47.5 ) — — — Other — 25.8 (4.3 ) (0.4 ) — — 21.1 Distributions and advances from (to) affiliates 355.1 213.2 (562.3 ) — — (6.0 ) — Net cash (used in) provided by financing activities — 227.0 (604.9 ) (51.4 ) — (6.0 ) (435.3 ) Effect of exchange rate changes on cash and cash equivalents — — — (2.7 ) — — (2.7 ) Net increase (decrease) in cash and cash equivalents — 107.2 — 17.1 — (13.4 ) 110.9 Cash and cash equivalents—beginning of period — 113.7 — 32.4 — (1.9 ) 144.2 Cash and cash equivalents—end of period $ — $ 220.9 $ — $ 49.5 $ — $ (15.3 ) $ 255.1

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On October 11, 2019, CDW extended the maturity date of the existing Term Loan to October 2026.

Description of Business and S_2

Description of Business and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Description of Business	Description of Business CDW Corporation ("Parent"), a Fortune 500 company and member of the S&P 500 Index, is a leading provider of integrated information technology ("IT") solutions with multi-national capabilities to small, medium and large business, government, education and healthcare customers in the United States ("US"), the United Kingdom ("UK") and Canada. The Company's offerings range from discrete hardware and software products to integrated IT solutions such as mobility, security, data center optimization, cloud computing, virtualization and collaboration. Throughout this report, the terms the "Company" and "CDW" refer to Parent and its 100% owned subsidiaries. Parent has two 100% owned subsidiaries, CDW LLC and CDW Finance Corporation. CDW LLC is an Illinois limited liability company that, together with its 100% owned subsidiaries, holds all material assets and conducts all business activities and operations of the Company. CDW Finance Corporation is a Delaware corporation formed for the sole purpose of acting as co-issuer of certain debt obligations as described in Note 13 (Supplemental Guarantor Information) and does not hold any material assets or engage in any business activities or operations.
Basis of Presentation	Basis of Presentation The accompanying unaudited interim Consolidated Financial Statements as of September 30, 2019 and for the three and nine months ended September 30, 2019 and 2018 (the "Consolidated Financial Statements") have been prepared in conformity with accounting principles generally accepted in the United States of America ("GAAP") and the rules and regulations of the US Securities and Exchange Commission (the "SEC") for interim financial statements. Accordingly, certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations of the SEC. These Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and the notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2018 (the " December 31, 2018 Consolidated Financial Statements"). The significant accounting policies used in preparing these Consolidated Financial Statements were applied on a basis consistent with those reflected in the December 31, 2018 Consolidated Financial Statements. In the opinion of management, the Consolidated Financial Statements contain all adjustments (consisting of a normal, recurring nature) necessary to present fairly the Company's financial position, results of operations, comprehensive income, cash flows and changes in stockholders' equity as of the dates and for the periods indicated. The unaudited results of operations for such interim periods reported are not necessarily indicative of results for the full year.
Principles of Consolidation	Principles of Consolidation The accompanying Consolidated Financial Statements include the accounts of Parent and its 100% owned subsidiaries. All intercompany transactions and accounts are eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the Consolidated Financial Statements in accordance with GAAP requires management to make use of certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the Consolidated Financial Statements and the reported amounts of revenue and expenses during the reported periods. The Company bases its estimates on historical experience and on various other assumptions that management believes are reasonable under the circumstances, the results of which form the basis for making judgments about carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates. The notes to the Consolidated Financial Statements contained in the December 31, 2018 Consolidated Financial Statements include a discussion of the significant accounting policies and estimates used in the preparation of the Company's Consolidated Financial Statements. Except as noted below for the adoption of Accounting Standards Update ("ASU") 2016-02, Leases ("Topic 842"), there have been no material changes to the Company's significant accounting policies and estimates during the nine months ended September 30, 2019 .
Leases	Leases The Company enters into operating lease contracts, as assessed at contract inception, primarily for real estate, data centers and equipment. On the Company's Consolidated Balance Sheets, Operating lease assets are included in Operating lease right-of-use assets and Operating lease liabilities are included in Other current liabilities and Long-term operating lease liabilities. At the lease commencement date, the Company records Operating lease liabilities based on the present value of the future lease payments. In determining the present value of future lease payments, the Company uses its incremental borrowing rate based on the information available at the commencement date. For real estate and data center contracts, the Company accounts for the lease and non-lease components as a single lease component. For certain equipment leases, the Company applies a portfolio approach to account for the right-of-use asset and operating lease liability. In assessing the lease term, the Company includes options to renew only when it is reasonably certain that it will be exercised; a determination which is at the sole discretion of the Company. Generally, for leases with an initial term of 12 months or less, the Company has elected to not record a right-of-use asset and lease liability. For equipment leases used in revenue generating activities, the Company will record a right-of-use asset and lease liability for leases with a term of 12 months or less. The Company records lease expense on a straight-line basis over the lease term beginning on the commencement date.
Recent Accounting Pronouncements	Measurement of Credit Losses on Financial Instruments In June 2016, the Financial Accounting Standards Board issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The ASU introduces a new forward-looking approach, based on expected losses, to estimate credit losses on certain types of financial instruments, including trade receivables. The estimate of expected credit losses will require considerations of historical information, current information and reasonable and supportable forecasts. The ASU also expands the disclosure requirements to enable users of financial statements to understand the assumptions, models and methods for estimating expected credit losses. The ASU will be adopted on January 1, 2020. The Company has established a cross-functional implementation team to analyze the effect of the ASU. The analysis includes identifying pools of receivables, evaluating and assessing estimation methodologies, assessing policy elections, and evaluating its business processes and internal controls to meet the ASU’s accounting, reporting and disclosure requirements. The Company is currently evaluating the impact the ASU will have on its Consolidated Financial Statements. Accounting for Leases On January 1, 2019, the Company adopted and applied Topic 842 resulting in the recognition of right-of-use assets and additional lease liabilities of $ 81 million as of January 1, 2019, mainly related to operating leases for the Company's real estate portfolio. For additional details regarding the impact to the Company's Consolidated Balance Sheets from adopting this standard, see Note 9 (Leases) .

Acquisition (Tables)

Acquisition (Tables)	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	The preliminary purchase price allocation is as follows: (in millions) Acquisition-Date Fair Value Net assets acquired $ 5.7 Identified intangible assets (1) 20.3 Goodwill (2) 62.0 Total purchase price $ 88.0 (1) Net of a related deferred tax liability of $7 million . (2) Goodwill in the amount of $62 million was recognized in connection with the acquisition of Scalar, primarily attributed to cross selling opportunities and overall corporate synergies. The full amount of goodwill recognized is not deductible for income tax purposes in Canada.

Inventory Financing Agreements

Inventory Financing Agreements (Tables)	9 Months Ended
	Sep. 30, 2019
Inventory Financing Agreements [Abstract]
Inventory Financing Agreements	Amounts included in Accounts payable-inventory financing are as follows: (in millions) September 30, 2019 December 31, 2018 Revolving Loan inventory financing agreement (1) $ 382.1 $ 406.3 Other inventory financing agreements 29.6 23.0 Accounts payable-inventory financing $ 411.7 $ 429.3 (1) The Senior Secured Asset-Based Revolving Credit Facility includes an inventory floorplan sub-facility that enables the Company to maintain an inventory financing agreement with a financial intermediary to facilitate the purchase of inventory from certain vendors on more favorable terms than offered directly by the vendors.

Contract Liabilities and Perf_2

Contract Liabilities and Performance Obligations (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	A contract's transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. The following table represents the total transaction price for the remaining performance obligations as of September 30, 2019 related to noncancelable contracts longer than 12 months in duration that is expected to be recognized over future periods. (in millions) Within 1 Year Years 1-2 Years 2-3 Thereafter Remaining performance obligations $ 40.2 $ 17.6 $ 5.1 $ 0.3

Financial Instruments (Tables)

Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Financial Instruments [Abstract]
Schedule of Interest Rate Derivatives	As of September 30, 2019 and December 31, 2018 , the Company had the following interest rate cap agreements for which the fair values are classified within Other assets on the Consolidated Balance Sheets: September 30, 2019 December 31, 2018 Notional Value (in millions) Effective Date Maturity Date Fair Value (in millions) Fair Value (in millions) $ 1,400.0 December 31, 2018 December 31, 2020 $ 0.1 $ 10.6 1,400.0 December 31, 2020 December 31, 2022 1.0 1.5 $ 1.1 $ 12.1

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	As of September 30, 2019 As of December 31, 2018 (dollars in millions) Maturity Interest Rate Amount Interest Rate Amount Credit Facilities CDW UK revolving credit facility (1) July 2021 — % $ — — % $ — Senior secured asset-based revolving credit facility March 2022 3.31 % 26.0 — % — Total credit facilities 26.0 — Term Loans CDW UK term loan (1) August 2021 2.16 % 56.5 2.29 % 65.0 Senior secured term loan facility (2) August 2023 3.80 % 1,442.0 4.10 % 1,453.2 Total term loans 1,498.5 1,518.2 Unsecured Senior Notes Senior notes due 2023 ("2023 Senior Notes") September 2023 — % — 5.00 % 525.0 Senior notes due 2024 ("2024 Senior Notes") December 2024 5.50 % 575.0 5.50 % 575.0 Senior notes due 2025 ("2025 Senior Notes") September 2025 5.00 % 600.0 5.00 % 600.0 Senior notes due 2028 ("2028 Senior Notes") April 2028 4.25 % 600.0 — % — Total unsecured senior notes 1,775.0 1,700.0 Other long-term obligations 4.4 8.3 Unamortized deferred financing fees (19.5 ) (17.9 ) Current maturities of long-term debt (25.4 ) (25.3 ) Total long-term debt $ 3,259.0 $ 3,183.3 (1) British pound-denominated debt facilities. (2) See Note 14 (Subsequent Events).
Carrying Value of Long-Term Debt	The approximate fair values and related carrying values of the Company's long-term debt, including current maturities and excluding unamortized discount and unamortized deferred financing fees, are as follows: (in millions) September 30, 2019 December 31, 2018 Fair value $ 3,412.3 $ 3,145.8 Carrying value 3,303.9 3,226.5

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Assets And Liabilities, Lessee	Supplemental Consolidated Balance Sheet information related to the Company's operating leases is as follows: (in millions) Classification on the Consolidated Balance Sheets September 30, 2019 Assets Operating lease right-of-use assets $ 84.2 Liabilities Current Accrued expenses and other current liabilities - Other $ 30.6 Long-term Long-term operating lease liabilities 81.7 Total lease liabilities $ 112.3 Lease term and discount rate September 30, 2019 Weighted average remaining lease term (years) 5.8 Weighted average discount rate 4.53 %
Lease, Cost	The components of operating lease expense are as follows: (in millions) Financial statement line item Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Cost of sales $ 43.9 $ 57.7 Selling and administrative expenses 7.0 21.9 Total lease cost $ 50.9 $ 79.6 Supplemental cash flow information related to operating leases is as follows: (in millions) Nine Months Ended September 30, 2019 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 79.5 Right-of-use assets obtained in exchange for lease obligations Operating leases $ 56.0
Lessee, Operating Lease, Liability, Maturity	Maturities of operating lease liabilities are as follows: (in millions) September 30, 2019 Remainder of 2019 $ 8.2 2020 31.5 2021 22.2 2022 15.0 2023 11.7 Thereafter 38.3 Total lease payments $ 126.9 Less: Interest (14.6 ) Present value of lease liabilities $ 112.3

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of Weighted Average Number of Shares	A reconciliation of basic weighted-average shares outstanding to diluted weighted-average shares outstanding is as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2019 2018 2019 2018 Basic weighted-average shares outstanding 144.5 150.9 145.7 151.6 Effect of dilutive securities (1) 2.7 2.8 2.5 2.5 Diluted weighted-average shares outstanding (2) 147.2 153.7 148.2 154.1 (1) The dilutive effect of outstanding stock options, restricted stock units, restricted stock, performance share units and Coworker Stock Purchase Plan units is reflected in the diluted weighted-average shares outstanding using the treasury stock method. (2) There were fewer than 0.1 million potential common shares excluded from diluted weighted-average shares outstanding for both the three and nine months ended September 30, 2019 and 2018 as their inclusion would have had an anti-dilutive effect.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Information about the Company's segments is as follows: (in millions) Corporate Small Business Public Other Headquarters Total Three Months Ended September 30, 2019 Net sales $ 1,913.5 $ 386.2 $ 2,100.9 $ 507.1 $ — $ 4,907.7 Operating income (loss) 138.9 27.2 168.4 21.9 (35.8 ) 320.6 Depreciation and amortization expense (21.7 ) (5.6 ) (15.0 ) (7.9 ) (18.0 ) (68.2 ) Three Months Ended September 30, 2018 Net sales $ 1,706.5 $ 340.0 $ 1,875.1 $ 451.6 $ — $ 4,373.2 Operating income (loss) 125.7 23.8 136.6 19.2 (30.5 ) 274.8 Depreciation and amortization expense (21.8 ) (5.5 ) (12.9 ) (7.3 ) (18.3 ) (65.8 ) (in millions) Corporate Small Business Public Other Headquarters Total Nine Months Ended September 30, 2019 Net sales $ 5,533.6 $ 1,119.2 $ 5,271.7 $ 1,571.0 $ — $ 13,495.5 Operating income (loss) 430.8 78.2 373.9 66.6 (99.7 ) 849.8 Depreciation and amortization expense (64.8 ) (16.8 ) (41.4 ) (23.1 ) (51.4 ) (197.5 ) Nine Months Ended September 30, 2018 Net sales $ 5,006.1 $ 997.1 $ 4,740.5 $ 1,422.0 $ — $ 12,165.7 Operating income (loss) 388.3 70.0 318.3 60.7 (92.9 ) 744.4 Depreciation and amortization expense (66.8 ) (16.6 ) (38.4 ) (25.1 ) (51.8 ) (198.7 )
Disaggregation of Revenue	Geographic Areas and Revenue Mix Three Months Ended September 30, 2019 (in millions) Corporate Small Business Public Other Total Geography (1) United States $ 1,910.9 $ 386.2 $ 2,100.9 $ 7.6 $ 4,405.6 Rest of World 2.6 — — 499.5 502.1 Total Net sales 1,913.5 386.2 2,100.9 507.1 4,907.7 Major Product and Services Hardware 1,528.0 326.6 1,711.3 358.3 3,924.2 Software 269.1 47.6 324.4 66.1 707.2 Services 97.9 6.7 59.0 80.2 243.8 Other (2) 18.5 5.3 6.2 2.5 32.5 Total Net sales 1,913.5 386.2 2,100.9 507.1 4,907.7 Sales by Channel Corporate 1,913.5 — — — 1,913.5 Small Business — 386.2 — — 386.2 Government — — 793.4 — 793.4 Education — — 807.0 — 807.0 Healthcare — — 500.5 — 500.5 Other — — — 507.1 507.1 Total Net sales 1,913.5 386.2 2,100.9 507.1 4,907.7 Timing of Revenue Recognition Transferred at a point in time where CDW is principal 1,743.4 364.0 1,939.3 443.8 4,490.5 Transferred at a point in time where CDW is agent 111.0 19.6 79.6 15.5 225.7 Transferred over time where CDW is principal 59.1 2.6 82.0 47.8 191.5 Total Net sales $ 1,913.5 $ 386.2 $ 2,100.9 $ 507.1 $ 4,907.7 (1) Net sales by geography is generally based on the ship-to address with the exception of certain services that may be performed at, or on behalf of, multiple locations. Such service arrangements are categorized based on the bill-to address. (2) Includes items such as delivery charges to customers. Three Months Ended September 30, 2018 (in millions) Corporate Small Business Public Other Total Geography (1) United States $ 1,704.1 $ 340.0 $ 1,875.1 $ 6.8 $ 3,926.0 Rest of World 2.4 — — 444.8 447.2 Total Net sales 1,706.5 340.0 1,875.1 451.6 4,373.2 Major Product and Services Hardware 1,379.5 284.0 1,530.8 363.6 3,557.9 Software 227.5 44.3 291.0 45.6 608.4 Services 83.1 6.6 48.8 40.5 179.0 Other (2) 16.4 5.1 4.5 1.9 27.9 Total Net sales 1,706.5 340.0 1,875.1 451.6 4,373.2 Sales by Channel Corporate 1,706.5 — — — 1,706.5 Small Business — 340.0 — — 340.0 Government — — 639.3 — 639.3 Education — — 793.1 — 793.1 Healthcare — — 442.7 — 442.7 Other — — — 451.6 451.6 Total Net sales 1,706.5 340.0 1,875.1 451.6 4,373.2 Timing of Revenue Recognition Transferred at a point in time where CDW is principal 1,571.6 321.0 1,764.6 402.8 4,060.0 Transferred at a point in time where CDW is agent 85.7 16.9 64.3 12.3 179.2 Transferred over time where CDW is principal 49.2 2.1 46.2 36.5 134.0 Total Net sales $ 1,706.5 $ 340.0 $ 1,875.1 $ 451.6 $ 4,373.2 (1) Net sales by geography is generally based on the ship-to address with the exception of certain services that may be performed at, or on behalf of, multiple locations. Such service arrangements are categorized based on the bill-to address. (2) Includes items such as delivery charges to customers. Nine Months Ended September 30, 2019 (in millions) Corporate Small Business Public Other Total Geography (1) United States $ 5,525.5 $ 1,119.2 $ 5,271.7 $ 24.8 $ 11,941.2 Rest of World 8.1 — — 1,546.2 1,554.3 Total Net sales 5,533.6 1,119.2 5,271.7 1,571.0 13,495.5 Major Product and Services Hardware 4,411.6 937.5 4,297.6 1,143.0 10,789.7 Software 784.8 145.0 808.0 213.3 1,951.1 Services 284.0 20.8 150.8 206.3 661.9 Other (2) 53.2 15.9 15.3 8.4 92.8 Total Net sales 5,533.6 1,119.2 5,271.7 1,571.0 13,495.5 Sales by Channel Corporate 5,533.6 — — — 5,533.6 Small Business — 1,119.2 — — 1,119.2 Government — — 1,860.2 — 1,860.2 Education — — 1,981.0 — 1,981.0 Healthcare — — 1,430.5 — 1,430.5 Other — — — 1,571.0 1,571.0 Total Net sales 5,533.6 1,119.2 5,271.7 1,571.0 13,495.5 Timing of Revenue Recognition Transferred at a point in time where CDW is principal 5,033.4 1,054.7 4,908.0 1,383.7 12,379.8 Transferred at a point in time where CDW is agent 333.7 59.4 190.9 42.0 626.0 Transferred over time where CDW is principal 166.5 5.1 172.8 145.3 489.7 Total Net sales $ 5,533.6 $ 1,119.2 $ 5,271.7 $ 1,571.0 $ 13,495.5 (1) Net sales by geography is generally based on the ship-to address with the exception of certain services that may be performed at, or on behalf of, multiple locations. Such service arrangements are categorized based on the bill-to address. (2) Includes items such as delivery charges to customers. Nine Months Ended September 30, 2018 (in millions) Corporate Small Business Public Other Total Geography (1) United States $ 4,999.9 $ 997.1 $ 4,740.5 $ 24.0 $ 10,761.5 Rest of World 6.2 — — 1,398.0 1,404.2 Total Net sales 5,006.1 997.1 4,740.5 1,422.0 12,165.7 Major Product and Services Hardware 4,013.4 829.4 3,876.7 1,136.9 9,856.4 Software 699.6 131.2 730.5 154.0 1,715.3 Services 242.3 20.6 120.5 124.8 508.2 Other (2) 50.8 15.9 12.8 6.3 85.8 Total Net sales 5,006.1 997.1 4,740.5 1,422.0 12,165.7 Sales by Channel Corporate 5,006.1 — — — 5,006.1 Small Business — 997.1 — — 997.1 Government — — 1,551.3 — 1,551.3 Education — — 1,902.4 — 1,902.4 Healthcare — — 1,286.8 — 1,286.8 Other — — — 1,422.0 1,422.0 Total Net sales 5,006.1 997.1 4,740.5 1,422.0 12,165.7 Timing of Revenue Recognition Transferred at a point in time where CDW is principal 4,581.3 940.0 4,445.8 1,277.4 11,244.5 Transferred at a point in time where CDW is agent 279.9 50.5 160.7 37.1 528.2 Transferred over time where CDW is principal 144.9 6.6 134.0 107.5 393.0 Total Net sales $ 5,006.1 $ 997.1 $ 4,740.5 $ 1,422.0 $ 12,165.7 (1) Net sales by geography is generally based on the ship-to address with the exception of certain services that may be performed at, or on behalf of, multiple locations. Such service arrangements are categorized based on the bill-to address. (2) Includes items such as delivery charges to customers. The following table presents Net sales by major category for the three and nine months ended September 30, 2019 and 2018 . Categories are based upon internal classifications. Three Months Ended September 30, 2019 2018 Dollars in Percentage Dollars in Percentage Notebooks/Mobile Devices $ 1,325.6 27.0 % $ 1,124.8 25.7 % Netcomm Products 567.3 11.6 582.4 13.3 Desktops 448.4 9.1 349.0 8.0 Video 353.3 7.2 320.5 7.3 Enterprise and Data Storage (Including Drives) 283.6 5.8 297.4 6.8 Other Hardware 946.0 19.3 883.8 20.3 Total Hardware 3,924.2 80.0 3,557.9 81.4 Software (1) 707.2 14.3 608.4 13.9 Services (1) 243.8 5.0 179.0 4.1 Other (2) 32.5 0.7 27.9 0.6 Total Net sales $ 4,907.7 100.0 % $ 4,373.2 100.0 % Nine Months Ended September 30, 2019 2018 Dollars in Percentage Dollars in Percentage Notebooks/Mobile Devices $ 3,537.5 26.2 % $ 3,069.4 25.2 % Netcomm Products 1,641.9 12.2 1,568.5 12.9 Desktops 1,183.6 8.8 1,013.2 8.3 Video 972.7 7.2 904.4 7.4 Enterprise and Data Storage (Including Drives) 849.2 6.3 816.2 6.7 Other Hardware 2,604.8 19.3 2,484.7 20.5 Total Hardware 10,789.7 80.0 9,856.4 81.0 Software (1) 1,951.1 14.4 1,715.3 14.1 Services (1) 661.9 4.9 508.2 4.2 Other (2) 92.8 0.7 85.8 0.7 Total Net sales $ 13,495.5 100.0 % $ 12,165.7 100.0 % (1) Certain software and services revenues are recorded on a net basis for accounting purposes. As a result, the category percentage of net revenues is not representative of the category percentage of gross profits. (2) Includes items such as delivery charges to customers.

Supplemental Guarantor Inform_2

Supplemental Guarantor Information (Tables)	9 Months Ended
	Sep. 30, 2019
Supplemental Guarantor Information [Abstract]
Condensed Consolidating Balance Sheets	The following tables set forth Condensed Consolidating Balance Sheets as of September 30, 2019 and December 31, 2018 , Consolidating Statements of Operations for the three and nine months ended September 30, 2019 and 2018 , Condensed Consolidating Statements of Comprehensive Income for the three and nine months ended September 30, 2019 and 2018 , and Condensed Consolidating Statements of Cash Flows for the nine months ended September 30, 2019 and 2018 , in accordance with Rule 3-10 of Regulation S-X. The consolidating financial information includes the accounts of CDW Corporation (the "Parent Guarantor"), which has no independent assets or operations, the accounts of CDW LLC (the "Subsidiary Issuer"), the combined accounts of the Guarantor Subsidiaries, the combined accounts of the Non-Guarantor Subsidiaries, and the accounts of CDW Finance Corporation (the "Co-Issuer") for the periods indicated. The information is prepared on the same basis as the Company's Consolidated Financial Statements. Condensed Consolidating Balance Sheet September 30, 2019 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Assets Current assets: Cash and cash equivalents $ — $ 124.1 $ — $ 78.5 $ — $ (35.7 ) $ 166.9 Accounts receivable, net — — 2,539.1 360.4 — — 2,899.5 Merchandise inventory — — 525.2 78.4 — — 603.6 Miscellaneous receivables — 103.1 300.6 28.5 — — 432.2 Prepaid expenses and other — 22.2 122.6 48.3 — — 193.1 Total current assets — 249.4 3,487.5 594.1 — (35.7 ) 4,295.3 Operating lease right-of-use assets — 23.2 33.1 27.9 — — 84.2 Property and equipment, net — 75.8 68.4 26.9 — — 171.1 Goodwill — 751.8 1,437.9 326.2 — — 2,515.9 Other intangible assets, net — 243.1 206.2 166.8 — — 616.1 Other assets 1.0 27.0 2.4 172.1 — (182.0 ) 20.5 Investment in and advances to subsidiaries 934.1 3,189.6 — — — (4,123.7 ) — Total Assets $ 935.1 $ 4,559.9 $ 5,235.5 $ 1,314.0 $ — $ (4,341.4 ) $ 7,703.1 Liabilities and Stockholders' Equity Current liabilities: Accounts payable-trade $ — $ 26.2 $ 1,701.9 $ 207.6 $ — $ (35.7 ) $ 1,900.0 Accounts payable-inventory financing — 0.1 382.0 29.6 — — 411.7 Current maturities of long-term debt — 14.9 4.2 6.3 — — 25.4 Contract liabilities — — 127.1 85.0 — — 212.1 Accrued expenses and other current liabilities — 256.0 352.0 83.8 — — 691.8 Total current liabilities — 297.2 2,567.2 412.3 — (35.7 ) 3,241.0 Long-term liabilities: Debt — 3,209.1 — 49.9 — — 3,259.0 Deferred income taxes — 51.7 32.0 28.7 — (1.1 ) 111.3 Operating lease liabilities — 33.0 25.2 23.5 — — 81.7 Other liabilities — 34.8 0.9 220.2 — (180.9 ) 75.0 Total long-term liabilities — 3,328.6 58.1 322.3 — (182.0 ) 3,527.0 Total stockholders' equity 935.1 934.1 2,610.2 579.4 — (4,123.7 ) 935.1 Total Liabilities and Stockholders' Equity $ 935.1 $ 4,559.9 $ 5,235.5 $ 1,314.0 $ — $ (4,341.4 ) $ 7,703.1 Condensed Consolidating Balance Sheet December 31, 2018 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Assets Current assets: Cash and cash equivalents $ — $ 176.0 $ — $ 46.7 $ — $ (16.9 ) $ 205.8 Accounts receivable, net — — 2,331.2 340.0 — — 2,671.2 Merchandise inventory — — 387.4 66.9 — — 454.3 Miscellaneous receivables — 110.6 187.7 18.1 — — 316.4 Prepaid expenses and other — 17.1 93.8 38.2 — — 149.1 Total current assets — 303.7 3,000.1 509.9 — (16.9 ) 3,796.8 Property and equipment, net — 82.3 52.0 21.8 — — 156.1 Goodwill — 751.8 1,437.8 273.2 — — 2,462.8 Other intangible assets, net — 252.5 300.0 159.7 — — 712.2 Other assets 1.4 49.8 9.6 140.2 — (161.2 ) 39.8 Investment in and advances to subsidiaries 973.8 3,028.9 — — — (4,002.7 ) — Total Assets $ 975.2 $ 4,469.0 $ 4,799.5 $ 1,104.8 $ — $ (4,180.8 ) $ 7,167.7 Liabilities and Stockholders' Equity Current liabilities: Accounts payable-trade $ — $ 39.2 $ 1,387.9 $ 166.9 $ — $ (16.9 ) $ 1,577.1 Accounts payable-inventory financing — 0.2 406.1 23.0 — — 429.3 Current maturities of long-term debt — 14.9 4.0 6.4 — — 25.3 Contract liabilities — — 95.6 82.7 — — 178.3 Accrued expenses and other current liabilities — 217.6 306.7 68.8 — — 593.1 Total current liabilities — 271.9 2,200.3 347.8 — (16.9 ) 2,803.1 Long-term liabilities: Debt — 3,121.3 4.3 57.7 — — 3,183.3 Deferred income taxes — 55.9 60.5 26.9 — (1.4 ) 141.9 Other liabilities — 46.1 5.7 172.2 — (159.8 ) 64.2 Total long-term liabilities — 3,223.3 70.5 256.8 — (161.2 ) 3,389.4 Total stockholders' equity 975.2 973.8 2,528.7 500.2 — (4,002.7 ) 975.2 Total Liabilities and Stockholders' Equity $ 975.2 $ 4,469.0 $ 4,799.5 $ 1,104.8 $ — $ (4,180.8 ) $ 7,167.7
Consolidating Statements of Operations	Consolidating Statement of Operations Three Months Ended September 30, 2019 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Net sales $ — $ — $ 4,400.6 $ 507.1 $ — $ — $ 4,907.7 Cost of sales — — 3,671.5 419.7 — — 4,091.2 Gross profit — — 729.1 87.4 — — 816.5 Selling and administrative expenses — 35.8 347.4 61.7 — — 444.9 Advertising expense — — 47.2 3.8 — — 51.0 Operating income (loss) — (35.8 ) 334.5 21.9 — — 320.6 Interest (expense) income, net — (42.0 ) 0.1 (0.4 ) — — (42.3 ) Other income, net — (16.1 ) — (1.3 ) — — (17.4 ) Income (loss) before income taxes — (93.9 ) 334.6 20.2 — — 260.9 Income tax (expense) benefit (0.1 ) 30.3 (87.9 ) (1.5 ) — — (59.2 ) Income (loss) before equity in earnings of subsidiaries (0.1 ) (63.6 ) 246.7 18.7 — — 201.7 Equity in earnings of subsidiaries 201.8 265.4 — — — (467.2 ) — Net income $ 201.7 $ 201.8 $ 246.7 $ 18.7 $ — $ (467.2 ) $ 201.7 Consolidating Statement of Operations Three Months Ended September 30, 2018 (in millions) Parent Subsidiary Guarantor Non-Guarantor Co-Issuer Consolidating Consolidated Net sales $ — $ — $ 3,921.6 $ 451.6 $ — $ — $ 4,373.2 Cost of sales — — 3,286.6 373.0 — — 3,659.6 Gross profit — — 635.0 78.6 — — 713.6 Selling and administrative expenses — 33.7 299.8 57.2 — — 390.7 Advertising expense — — 45.9 2.2 — — 48.1 Operating income (loss) — (33.7 ) 289.3 19.2 — — 274.8 Interest (expense) income, net — (36.1 ) 0.9 (1.4 ) — — (36.6 ) Other income, net — — 0.1 0.1 — — 0.2 Income (loss) before income taxes — (69.8 ) 290.3 17.9 — — 238.4 Income tax (expense) benefit (0.1 ) 20.5 (75.3 ) 0.2 — — (54.7 ) Income (loss) before equity in earnings of subsidiaries (0.1 ) (49.3 ) 215.0 18.1 — — 183.7 Equity in earnings of subsidiaries 183.8 233.1 — — — (416.9 ) — Net income $ 183.7 $ 183.8 $ 215.0 $ 18.1 $ — $ (416.9 ) $ 183.7 Consolidating Statement of Operations Nine Months Ended September 30, 2019 (in millions) Parent Subsidiary Guarantor Non-Guarantor Co-Issuer Consolidating Consolidated Net sales $ — $ — $ 11,924.5 $ 1,571.0 $ — $ — $ 13,495.5 Cost of sales — — 9,926.3 1,306.8 — — 11,233.1 Gross profit — — 1,998.2 264.2 — — 2,262.4 Selling and administrative expenses — 99.7 980.6 189.0 — — 1,269.3 Advertising expense — — 134.7 8.6 — — 143.3 Operating income (loss) — (99.7 ) 882.9 66.6 — — 849.8 Interest (expense) income, net — (120.2 ) 0.3 (1.2 ) — — (121.1 ) Other (expense) income, net — (16.1 ) 2.1 (1.0 ) — — (15.0 ) Income (loss) before income taxes — (236.0 ) 885.3 64.4 — — 713.7 Income tax (expense) benefit (0.3 ) 75.2 (229.2 ) (8.2 ) — — (162.5 ) Income (loss) before equity in earnings of subsidiaries (0.3 ) (160.8 ) 656.1 56.2 — — 551.2 Equity in earnings of subsidiaries 551.5 712.3 — — — (1,263.8 ) — Net income $ 551.2 $ 551.5 $ 656.1 $ 56.2 $ — $ (1,263.8 ) $ 551.2 Consolidating Statement of Operations Nine Months Ended September 30, 2018 (in millions) Parent Subsidiary Guarantor Non-Guarantor Co-Issuer Consolidating Consolidated Net sales $ — $ — $ 10,743.7 $ 1,422.0 $ — $ — $ 12,165.7 Cost of sales — — 8,966.6 1,186.0 — — 10,152.6 Gross profit — — 1,777.1 236.0 — — 2,013.1 Selling and administrative expenses — 103.3 861.8 169.7 — — 1,134.8 Advertising expense — — 128.3 5.6 — — 133.9 Operating income (loss) — (103.3 ) 787.0 60.7 — — 744.4 Interest (expense) income, net — (109.9 ) 2.8 (4.4 ) — — (111.5 ) Other income, net — — 0.6 0.4 — — 1.0 Income (loss) before income taxes — (213.2 ) 790.4 56.7 — — 633.9 Income tax (expense) benefit (0.3 ) 61.5 (202.6 ) (8.8 ) — — (150.2 ) Income (loss) before equity in earnings of subsidiaries (0.3 ) (151.7 ) 587.8 47.9 — — 483.7 Equity in earnings of subsidiaries 484.0 635.7 — — — (1,119.7 ) — Net income $ 483.7 $ 484.0 $ 587.8 $ 47.9 $ — $ (1,119.7 ) $ 483.7
Condensed Statement of Comprehensive Income	Condensed Consolidating Statement of Comprehensive Income Three Months Ended September 30, 2019 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Comprehensive income $ 187.0 $ 187.1 $ 246.7 $ 4.1 $ — $ (437.9 ) $ 187.0 Condensed Consolidating Statement of Comprehensive Income Three Months Ended September 30, 2018 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Comprehensive income $ 180.6 $ 180.7 $ 215.0 $ 14.9 $ — $ (410.6 ) $ 180.6 Condensed Consolidating Statement of Comprehensive Income Nine Months Ended September 30, 2019 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Comprehensive income $ 527.7 $ 528.0 $ 656.1 $ 43.5 $ — $ (1,227.6 ) $ 527.7 Condensed Consolidating Statement of Comprehensive Income Nine Months Ended September 30, 2018 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Comprehensive income $ 471.4 $ 471.7 $ 587.8 $ 30.0 $ — $ (1,089.5 ) $ 471.4
Condensed Consolidating Statements Cash Flows	Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2019 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Net cash provided by (used in) operating activities $ — $ (6.3 ) $ 620.6 $ 95.4 $ — $ (27.4 ) $ 682.3 Cash flows used in investing activities: Capital expenditures — (46.4 ) (19.5 ) (9.1 ) — — (75.0 ) Acquisition of business, net of cash acquired — — — (75.0 ) — — (75.0 ) Net cash used in investing activities — (46.4 ) (19.5 ) (84.1 ) — — (150.0 ) Cash flows (used in) provided by financing activities: Proceeds from borrowings under revolving credit facility — 1,860.5 — — — — 1,860.5 Repayments of borrowings under revolving credit facility — (1,834.5 ) — — — — (1,834.5 ) Repayments of long-term debt — (11.0 ) — (8.7 ) — — (19.7 ) Proceeds from issuance of long-term debt — 600.0 — — — — 600.0 Payments to extinguish long-term debt — (538.1 ) — — — — (538.1 ) Net change in accounts payable-inventory financing — — (24.2 ) 6.8 — — (17.4 ) Repurchases of common stock (493.3 ) — — — — — (493.3 ) Payment of incentive compensation plan withholding taxes (21.3 ) — — — — — (21.3 ) Dividend payments (128.9 ) — — — — — (128.9 ) Capital contributions — (76.0 ) — 76.0 — — — Other — 28.8 (4.4 ) (0.2 ) — — 24.2 Distributions and advances from (to) affiliates 643.5 (28.9 ) (572.5 ) (50.7 ) — 8.6 — Net cash (used in) provided by financing activities — 0.8 (601.1 ) 23.2 — 8.6 (568.5 ) Effect of exchange rate changes on cash and cash equivalents — — — (2.7 ) — — (2.7 ) Net (decrease) increase in cash and cash equivalents — (51.9 ) — 31.8 — (18.8 ) (38.9 ) Cash and cash equivalents—beginning of period — 176.0 — 46.7 — (16.9 ) 205.8 Cash and cash equivalents—end of period $ — $ 124.1 $ — $ 78.5 $ — $ (35.7 ) $ 166.9 Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2018 (in millions) Parent Guarantor Subsidiary Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Co-Issuer Consolidating Adjustments Consolidated Net cash provided by (used in) operating activities $ — $ (78.9 ) $ 608.4 $ 80.2 $ — $ (7.4 ) $ 602.3 Cash flows used in investing activities: Capital expenditures — (40.9 ) (3.5 ) (9.0 ) — — (53.4 ) Net cash used in investing activities — (40.9 ) (3.5 ) (9.0 ) — — (53.4 ) Cash flows (used in) provided by financing activities: Proceeds from borrowings under revolving credit facility — 640.0 — 48.9 — — 688.9 Repayments of borrowings under revolving credit facility — (640.0 ) — (41.9 ) — — (681.9 ) Repayments of long-term debt — (11.2 ) — (7.0 ) — — (18.2 ) Net change in accounts payable-inventory financing — (0.8 ) (85.8 ) (3.5 ) — — (90.1 ) Repurchases of common stock (232.5 ) — — — — — (232.5 ) Payment of incentive compensation plan withholding taxes (27.1 ) — — — — — (27.1 ) Dividend payments (95.5 ) — — — — — (95.5 ) Repayment of intercompany loan — — 47.5 (47.5 ) — — — Other — 25.8 (4.3 ) (0.4 ) — — 21.1 Distributions and advances from (to) affiliates 355.1 213.2 (562.3 ) — — (6.0 ) — Net cash (used in) provided by financing activities — 227.0 (604.9 ) (51.4 ) — (6.0 ) (435.3 ) Effect of exchange rate changes on cash and cash equivalents — — — (2.7 ) — — (2.7 ) Net increase (decrease) in cash and cash equivalents — 107.2 — 17.1 — (13.4 ) 110.9 Cash and cash equivalents—beginning of period — 113.7 — 32.4 — (1.9 ) 144.2 Cash and cash equivalents—end of period $ — $ 220.9 $ — $ 49.5 $ — $ (15.3 ) $ 255.1

Description of Business and S_3

Description of Business and Summary of Significant Accounting Policies (Details)	Sep. 30, 2019subsidiary
Accounting Policies [Abstract]
Number of owned subsidiaries	2

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 84.2
Operating lease, liability	$ 112.3
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		$ 81
Operating lease, liability		$ 81

Acquisition - Narrative (Detail

Acquisition - Narrative (Details) - Scalar $ in Millions	Feb. 01, 2019USD ($)
Business Acquisition [Line Items]
Total purchase price	$ 88
Deferred consideration transferred	$ 13

Acquisition - Preliminary Purch

Acquisition - Preliminary Purchase Price Allocation (Details) - USD ($) $ in Millions	Feb. 01, 2019	Sep. 30, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill		$ 2,515.9	$ 2,462.8
Scalar
Business Acquisition [Line Items]
Net assets acquired	$ 5.7
Identified intangible assets	20.3
Goodwill	62
Total purchase price	88
Intangible assets, deferred tax liability	$ 7

Inventory Financing Agreement_2

Inventory Financing Agreements (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Inventory Financing Agreements [Line Items]
Accounts payable-inventory financing	$ 411.7	$ 429.3
Accounts Payable, Inventory Financing
Inventory Financing Agreements [Line Items]
Revolving Loan inventory financing agreement	382.1	406.3
Other inventory financing agreements	$ 29.6	$ 23

Contract Liabilities and Perf_3

Contract Liabilities and Performance Obligations - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Contract liabilities	$ 212		$ 178
Revenue recognized from contract with customer	$ 117	$ 153

Contract Liabilities and Perf_4

Contract Liabilities and Performance Obligations - Schedule of Remaining Performance Obligations (Details) $ in Millions	Sep. 30, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations, expected timing of satisfaction, period	3 months
Remaining performance obligations	$ 40.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations, expected timing of satisfaction, period	1 year
Remaining performance obligations	$ 17.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations, expected timing of satisfaction, period	1 year
Remaining performance obligations	$ 5.1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations, expected timing of satisfaction, period
Remaining performance obligations	$ 0.3

Financial Instruments - Narrati

Financial Instruments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest Rate Cap
Derivative [Line Items]
Notional amount		$ 1,200
Cap agreement effective 12/31/18-12/31/20
Derivative [Line Items]
Notional amount		1,400
Premium payments on interest rate cap agreements		6
Interest Rate Contract
Derivative [Line Items]
Unrealized gain (loss) on effective portion of interest rate cap agreements		(13)
Unrealized gain (loss) on effective portion of interest rate cap agreements	$ (1)		$ 3
Amount expected to be reclassified from AOCL to interest expense in next twelve months		7
Derivative
Derivative [Line Items]
Interest income (expense) reclassified into earnings	$ (1)	$ (2)	$ (3)

Financial Instruments - Schedul

Financial Instruments - Schedule of Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Interest rate cap, fair value	$ 1.1	$ 12.1
Cap agreement effective 12/31/18-12/31/20
Derivative [Line Items]
Notional amount	1,400
Interest rate cap, fair value	0.1	10.6
Cap agreement effective 12/31/20-12/31/22
Derivative [Line Items]
Notional amount	1,400
Interest rate cap, fair value	$ 1	$ 1.5

Long-Term Debt - Debt Balances

Long-Term Debt - Debt Balances and Interest Rates (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term debt	$ 3,303.9	$ 3,226.5
Unamortized deferred financing fees	(19.5)	(17.9)
Current maturities of long-term debt	(25.4)	(25.3)
Total long-term debt	$ 3,259	$ 3,183.3
CDW UK revolving credit facility
Debt Instrument [Line Items]
Interest rate in effect	0.00%	0.00%
Long-term debt	$ 0	$ 0
Senior secured asset-based revolving credit facility
Debt Instrument [Line Items]
Interest rate in effect	3.31%	0.00%
Long-term debt	$ 26	$ 0
Total credit facilities
Debt Instrument [Line Items]
Long-term debt	$ 26	$ 0
CDW UK term loan
Debt Instrument [Line Items]
Interest rate in effect	2.16%	2.29%
Long-term debt	$ 56.5	$ 65
Senior secured term loan facility
Debt Instrument [Line Items]
Interest rate in effect	3.80%	4.10%
Long-term debt	$ 1,442	$ 1,453.2
Total term loans
Debt Instrument [Line Items]
Long-term debt	$ 1,498.5	$ 1,518.2
Senior notes due 2023
Debt Instrument [Line Items]
Interest rate in effect	0.00%	5.00%
Long-term debt	$ 0	$ 525
Senior notes due 2024
Debt Instrument [Line Items]
Interest rate in effect	5.50%	5.50%
Long-term debt	$ 575	$ 575
Senior notes due 2025
Debt Instrument [Line Items]
Interest rate in effect	5.00%	5.00%
Long-term debt	$ 600	$ 600
Senior Notes due 2028
Debt Instrument [Line Items]
Interest rate in effect	4.25%	0.00%
Long-term debt	$ 600	$ 0
Total unsecured senior notes
Debt Instrument [Line Items]
Long-term debt	1,775	1,700
Other long-term obligations
Debt Instrument [Line Items]
Long-term debt	$ 4.4	$ 8.3

Long-Term Debt - Narrative (Det

Long-Term Debt - Narrative (Details) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2019GBP (£)	Sep. 30, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2019USD ($)
Debt Instrument [Line Items]
Long-term debt			$ 3,226.5	$ 3,303.9
Senior secured term loan facility
Debt Instrument [Line Items]
Amount of restricted payment capacity under the loan				1,700
Periodic payment, principal		$ 4
Long-term debt			$ 1,453.2	$ 1,442
Interest rate in effect	3.80%		4.10%	3.80%
CDW UK term loan
Debt Instrument [Line Items]
Annual principal repayment installments	£ 5,000,000	$ 6
Amount of restricted payment capacity under the loan	£ 134,000,000			$ 165
Long-term debt			$ 65	$ 56.5
Interest rate in effect	2.16%		2.29%	2.16%
CDW UK revolving credit facility
Debt Instrument [Line Items]
Borrowing capacity of the Revolving Loan	£ 50,000,000			$ 61
Long-term debt			$ 0	$ 0
Interest rate in effect	0.00%		0.00%	0.00%
Senior secured asset-based revolving credit facility
Debt Instrument [Line Items]
Undrawn letters of credit				$ 1
Borrowing base				2,200
Additional borrowing capacity				1,100
Long-term debt			$ 0	$ 26
Interest rate in effect	3.31%		0.00%	3.31%
Senior notes due 2025
Debt Instrument [Line Items]
Long-term debt			$ 600	$ 600
Interest rate in effect	5.00%		5.00%	5.00%
Total term loans
Debt Instrument [Line Items]
Long-term debt			$ 1,518.2	$ 1,498.5
Senior Notes due 2028
Debt Instrument [Line Items]
Long-term debt			$ 0	$ 600
Interest rate in effect	4.25%		0.00%	4.25%
Senior notes due 2023
Debt Instrument [Line Items]
Long-term debt			$ 525	$ 0
Interest rate in effect	0.00%		5.00%	0.00%
Redemption price, percentage			102.50%
Accounts Payable, Inventory Financing | Senior secured asset-based revolving credit facility
Debt Instrument [Line Items]
Amount owed under Revolving loan financing agreement				$ 356

Long-Term Debt - Fair Value of

Long-Term Debt - Fair Value of Long-Term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value	$ 3,303.9	$ 3,226.5
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value	$ 3,412.3	$ 3,145.8

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income tax (expense) benefit	$ (59.2)	$ (54.7)	$ (162.5)	$ (150.2)
Effective income tax rate reconciliation, percent	22.70%	22.90%	22.80%	23.70%

Leases - Supplemental Consolida

Leases - Supplemental Consolidated Balance Sheet information Related Operating Leases (Details) $ in Millions	Sep. 30, 2019USD ($)
Leases [Abstract]
Operating lease right-of-use assets	$ 84.2
Accrued expenses and other current liabilities - Other	30.6
Long-term operating lease liabilities	81.7
Operating lease liabilities	$ 112.3
Weighted average remaining lease term (years)	5 years 9 months 18 days
Weighted average discount rate	4.53%

Leases - Operating Lease Expens

Leases - Operating Lease Expenses (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Lessee, Lease, Description [Line Items]
Lease cost	$ 50.9	$ 79.6
Cost of sales
Lessee, Lease, Description [Line Items]
Lease cost	43.9	57.7
Selling and administrative expenses
Lessee, Lease, Description [Line Items]
Lease cost	$ 7	$ 21.9

Leases - Maturities of Operatin

Leases - Maturities of Operating Lease Liabilities (Details) $ in Millions	Sep. 30, 2019USD ($)
Leases [Abstract]
Remainder of 2019	$ 8.2
2020	31.5
2021	22.2
2022	15
2023	11.7
Thereafter	38.3
Total lease payments	126.9
Less: Interest	(14.6)
Present value of lease liabilities	$ 112.3

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information Related to Operating Leases (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 79.5
Right-of-use assets obtained in exchange for lease obligations
Operating leases	$ 56

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	Sep. 30, 2019USD ($)
Lessee, Lease, Description [Line Items]
Additional operating lease commitment	$ 99
Operating lease term of contract	17 years
Minimum
Lessee, Lease, Description [Line Items]
Lease terms of contract	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease terms of contract	17 years

Earnings per Share (Details)

Earnings per Share (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Basic weighted-average shares outstanding (in shares)	144.5	150.9	145.7	151.6
Effect of dilutive securities	2.7	2.8	2.5	2.5
Diluted weighted-average shares outstanding (in shares)	147.2	153.7	148.2	154.1
Anti-dilutive shares (fewer than) (in shares)	0.1	0.1	0.1	0.1

Segment Information - Narrative

Segment Information - Narrative (Details)	9 Months Ended
	Sep. 30, 2019employeesegment
Segment Reporting Information [Line Items]
Number of reportable segments | segment	3
Number of operating segments which do not meet reportable unit quantitative threshold | segment	2
Minimum | Corporate
Segment Reporting Information [Line Items]
Customer segments, customer employee headcount | employee	250
Maximum | Small Business
Segment Reporting Information [Line Items]
Customer segments, customer employee headcount | employee	250

Segment Information - Schedule

Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Net sales	$ 4,907.7	$ 4,373.2	$ 13,495.5	$ 12,165.7
Income (loss) from operations	320.6	274.8	849.8	744.4
Depreciation and amortization expense	(68.2)	(65.8)	(197.5)	(198.7)
Operating Segments | Corporate
Segment Reporting Information [Line Items]
Net sales	1,913.5	1,706.5	5,533.6	5,006.1
Income (loss) from operations	138.9	125.7	430.8	388.3
Depreciation and amortization expense	(21.7)	(21.8)	(64.8)	(66.8)
Operating Segments | Small Business
Segment Reporting Information [Line Items]
Net sales	386.2	340	1,119.2	997.1
Income (loss) from operations	27.2	23.8	78.2	70
Depreciation and amortization expense	(5.6)	(5.5)	(16.8)	(16.6)
Operating Segments | Public
Segment Reporting Information [Line Items]
Net sales	2,100.9	1,875.1	5,271.7	4,740.5
Income (loss) from operations	168.4	136.6	373.9	318.3
Depreciation and amortization expense	(15)	(12.9)	(41.4)	(38.4)
Operating Segments | Other
Segment Reporting Information [Line Items]
Net sales	507.1	451.6	1,571	1,422
Income (loss) from operations	21.9	19.2	66.6	60.7
Depreciation and amortization expense	(7.9)	(7.3)	(23.1)	(25.1)
Headquarters
Segment Reporting Information [Line Items]
Net sales	0	0	0	0
Income (loss) from operations	(35.8)	(30.5)	(99.7)	(92.9)
Depreciation and amortization expense	$ (18)	$ (18.3)	$ (51.4)	$ (51.8)

Segment Information - Disaggreg

Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 4,907.7	$ 4,373.2	$ 13,495.5	$ 12,165.7
Percentage of Total Net Sales	100.00%	100.00%	100.00%	100.00%
Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	$ 1,913.5	$ 1,706.5	$ 5,533.6	$ 5,006.1
Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	386.2	340	1,119.2	997.1
Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	2,100.9	1,875.1	5,271.7	4,740.5
Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	507.1	451.6	1,571	1,422
Transferred at a point in time where CDW is principal
Disaggregation of Revenue [Line Items]
Net sales	4,490.5	4,060	12,379.8	11,244.5
Transferred at a point in time where CDW is principal | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	1,743.4	1,571.6	5,033.4	4,581.3
Transferred at a point in time where CDW is principal | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	364	321	1,054.7	940
Transferred at a point in time where CDW is principal | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	1,939.3	1,764.6	4,908	4,445.8
Transferred at a point in time where CDW is principal | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	443.8	402.8	1,383.7	1,277.4
Transferred at a point in time where CDW is agent
Disaggregation of Revenue [Line Items]
Net sales	225.7	179.2	626	528.2
Transferred at a point in time where CDW is agent | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	111	85.7	333.7	279.9
Transferred at a point in time where CDW is agent | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	19.6	16.9	59.4	50.5
Transferred at a point in time where CDW is agent | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	79.6	64.3	190.9	160.7
Transferred at a point in time where CDW is agent | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	15.5	12.3	42	37.1
Transferred over time where CDW is principal
Disaggregation of Revenue [Line Items]
Net sales	191.5	134	489.7	393
Transferred over time where CDW is principal | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	59.1	49.2	166.5	144.9
Transferred over time where CDW is principal | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	2.6	2.1	5.1	6.6
Transferred over time where CDW is principal | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	82	46.2	172.8	134
Transferred over time where CDW is principal | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	47.8	36.5	145.3	107.5
Corporate
Disaggregation of Revenue [Line Items]
Net sales	1,913.5	1,706.5	5,533.6	5,006.1
Corporate | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	1,913.5	1,706.5	5,533.6	5,006.1
Corporate | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Corporate | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Corporate | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Small Business
Disaggregation of Revenue [Line Items]
Net sales	386.2	340	1,119.2	997.1
Small Business | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Small Business | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	386.2	340	1,119.2	997.1
Small Business | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Small Business | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Government
Disaggregation of Revenue [Line Items]
Net sales	793.4	639.3	1,860.2	1,551.3
Government | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Government | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Government | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	793.4	639.3	1,860.2	1,551.3
Government | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Education
Disaggregation of Revenue [Line Items]
Net sales	807	793.1	1,981	1,902.4
Education | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Education | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Education | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	807	793.1	1,981	1,902.4
Education | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Healthcare
Disaggregation of Revenue [Line Items]
Net sales	500.5	442.7	1,430.5	1,286.8
Healthcare | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Healthcare | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Healthcare | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	500.5	442.7	1,430.5	1,286.8
Healthcare | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other
Disaggregation of Revenue [Line Items]
Net sales	507.1	451.6	1,571	1,422
Other | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Other | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	507.1	451.6	1,571	1,422
Notebooks/Mobile Devices
Disaggregation of Revenue [Line Items]
Net sales	$ 1,325.6	$ 1,124.8	$ 3,537.5	$ 3,069.4
Percentage of Total Net Sales	27.00%	25.70%	26.20%	25.20%
Netcomm Products
Disaggregation of Revenue [Line Items]
Net sales	$ 567.3	$ 582.4	$ 1,641.9	$ 1,568.5
Percentage of Total Net Sales	11.60%	13.30%	12.20%	12.90%
Desktops
Disaggregation of Revenue [Line Items]
Net sales	$ 448.4	$ 349	$ 1,183.6	$ 1,013.2
Percentage of Total Net Sales	9.10%	8.00%	8.80%	8.30%
Video
Disaggregation of Revenue [Line Items]
Net sales	$ 353.3	$ 320.5	$ 972.7	$ 904.4
Percentage of Total Net Sales	7.20%	7.30%	7.20%	7.40%
Enterprise and Data Storage (Including Drives)
Disaggregation of Revenue [Line Items]
Net sales	$ 283.6	$ 297.4	$ 849.2	$ 816.2
Percentage of Total Net Sales	5.80%	6.80%	6.30%	6.70%
Other Hardware
Disaggregation of Revenue [Line Items]
Net sales	$ 946	$ 883.8	$ 2,604.8	$ 2,484.7
Percentage of Total Net Sales	19.30%	20.30%	19.30%	20.50%
Hardware
Disaggregation of Revenue [Line Items]
Net sales	$ 3,924.2	$ 3,557.9	$ 10,789.7	$ 9,856.4
Percentage of Total Net Sales	80.00%	81.40%	80.00%	81.00%
Hardware | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	$ 1,528	$ 1,379.5	$ 4,411.6	$ 4,013.4
Hardware | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	326.6	284	937.5	829.4
Hardware | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	1,711.3	1,530.8	4,297.6	3,876.7
Hardware | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	358.3	363.6	1,143	1,136.9
Software
Disaggregation of Revenue [Line Items]
Net sales	$ 707.2	$ 608.4	$ 1,951.1	$ 1,715.3
Percentage of Total Net Sales	14.30%	13.90%	14.40%	14.10%
Software | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	$ 269.1	$ 227.5	$ 784.8	$ 699.6
Software | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	47.6	44.3	145	131.2
Software | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	324.4	291	808	730.5
Software | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	66.1	45.6	213.3	154
Services
Disaggregation of Revenue [Line Items]
Net sales	$ 243.8	$ 179	$ 661.9	$ 508.2
Percentage of Total Net Sales	5.00%	4.10%	4.90%	4.20%
Services | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	$ 97.9	$ 83.1	$ 284	$ 242.3
Services | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	6.7	6.6	20.8	20.6
Services | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	59	48.8	150.8	120.5
Services | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	80.2	40.5	206.3	124.8
Other
Disaggregation of Revenue [Line Items]
Net sales	$ 32.5	$ 27.9	$ 92.8	$ 85.8
Percentage of Total Net Sales	0.70%	0.60%	0.70%	0.70%
Other | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	$ 18.5	$ 16.4	$ 53.2	$ 50.8
Other | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	5.3	5.1	15.9	15.9
Other | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	6.2	4.5	15.3	12.8
Other | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	2.5	1.9	8.4	6.3
United States
Disaggregation of Revenue [Line Items]
Net sales	4,405.6	3,926	11,941.2	10,761.5
United States | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	1,910.9	1,704.1	5,525.5	4,999.9
United States | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	386.2	340	1,119.2	997.1
United States | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	2,100.9	1,875.1	5,271.7	4,740.5
United States | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	7.6	6.8	24.8	24
Rest of World
Disaggregation of Revenue [Line Items]
Net sales	502.1	447.2	1,554.3	1,404.2
Rest of World | Operating Segments | Corporate
Disaggregation of Revenue [Line Items]
Net sales	2.6	2.4	8.1	6.2
Rest of World | Operating Segments | Small Business
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Rest of World | Operating Segments | Public
Disaggregation of Revenue [Line Items]
Net sales	0	0	0	0
Rest of World | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Net sales	$ 499.5	$ 444.8	$ 1,546.2	$ 1,398

Supplemental Guarantor Inform_3

Supplemental Guarantor Information - Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 166.9		$ 205.8
Accounts receivable, net	2,899.5		2,671.2
Merchandise inventory	603.6		454.3
Miscellaneous receivables	432.2		316.4
Prepaid expenses and other	193.1		149.1
Total current assets	4,295.3		3,796.8
Operating lease right-of-use assets	84.2
Property and equipment, net	171.1		156.1
Goodwill	2,515.9		2,462.8
Other intangible assets, net	616.1		712.2
Other assets	20.5		39.8
Investment in and advances to subsidiaries	0		0
Total Assets	7,703.1		7,167.7
Current liabilities:
Accounts payable-trade	1,900		1,577.1
Accounts payable-inventory financing	411.7		429.3
Current maturities of long-term debt	25.4		25.3
Contract liabilities	212.1		178.3
Accrued expenses and other current liabilities	691.8		593.1
Total current liabilities	3,241		2,803.1
Long-term liabilities:
Debt	3,259		3,183.3
Deferred income taxes	111.3		141.9
Operating lease liabilities	81.7
Other liabilities	75		64.2
Total long-term liabilities	3,527		3,389.4
Total stockholders' equity	935.1	$ 936.1	975.2	$ 1,160.7	$ 1,068.9	$ 985.6
Total Liabilities and Stockholders' Equity	7,703.1		7,167.7
Reportable Legal Entities
Current assets:
Operating lease right-of-use assets	0
Consolidating Adjustments
Current assets:
Cash and cash equivalents	(35.7)		(16.9)
Accounts receivable, net	0		0
Merchandise inventory	0		0
Miscellaneous receivables	0		0
Prepaid expenses and other	0		0
Total current assets	(35.7)		(16.9)
Operating lease right-of-use assets	0
Property and equipment, net	0		0
Goodwill	0		0
Other intangible assets, net	0		0
Other assets	(182)		(161.2)
Investment in and advances to subsidiaries	(4,123.7)		(4,002.7)
Total Assets	(4,341.4)		(4,180.8)
Current liabilities:
Accounts payable-trade	(35.7)		(16.9)
Accounts payable-inventory financing	0		0
Current maturities of long-term debt	0		0
Contract liabilities	0		0
Accrued expenses and other current liabilities	0		0
Total current liabilities	(35.7)		(16.9)
Long-term liabilities:
Debt	0		0
Deferred income taxes	(1.1)		(1.4)
Operating lease liabilities	0
Other liabilities	(180.9)		(159.8)
Total long-term liabilities	(182)		(161.2)
Total stockholders' equity	(4,123.7)		(4,002.7)
Total Liabilities and Stockholders' Equity	(4,341.4)		(4,180.8)
Parent Guarantor | Reportable Legal Entities
Current assets:
Cash and cash equivalents	0		0
Accounts receivable, net	0		0
Merchandise inventory	0		0
Miscellaneous receivables	0		0
Prepaid expenses and other	0		0
Total current assets	0		0
Operating lease right-of-use assets	0
Property and equipment, net	0		0
Goodwill	0		0
Other intangible assets, net	0		0
Other assets	1		1.4
Investment in and advances to subsidiaries	934.1		973.8
Total Assets	935.1		975.2
Current liabilities:
Accounts payable-trade	0		0
Accounts payable-inventory financing	0		0
Current maturities of long-term debt	0		0
Contract liabilities	0		0
Accrued expenses and other current liabilities	0		0
Total current liabilities	0		0
Long-term liabilities:
Debt	0		0
Deferred income taxes	0		0
Operating lease liabilities	0
Other liabilities	0		0
Total long-term liabilities	0		0
Total stockholders' equity	935.1		975.2
Total Liabilities and Stockholders' Equity	935.1		975.2
Subsidiary Issuer | Reportable Legal Entities
Current assets:
Cash and cash equivalents	124.1		176
Accounts receivable, net	0		0
Merchandise inventory	0		0
Miscellaneous receivables	103.1		110.6
Prepaid expenses and other	22.2		17.1
Total current assets	249.4		303.7
Operating lease right-of-use assets	23.2
Property and equipment, net	75.8		82.3
Goodwill	751.8		751.8
Other intangible assets, net	243.1		252.5
Other assets	27		49.8
Investment in and advances to subsidiaries	3,189.6		3,028.9
Total Assets	4,559.9		4,469
Current liabilities:
Accounts payable-trade	26.2		39.2
Accounts payable-inventory financing	0.1		0.2
Current maturities of long-term debt	14.9		14.9
Contract liabilities	0		0
Accrued expenses and other current liabilities	256		217.6
Total current liabilities	297.2		271.9
Long-term liabilities:
Debt	3,209.1		3,121.3
Deferred income taxes	51.7		55.9
Operating lease liabilities	33
Other liabilities	34.8		46.1
Total long-term liabilities	3,328.6		3,223.3
Total stockholders' equity	934.1		973.8
Total Liabilities and Stockholders' Equity	4,559.9		4,469
Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	0		0
Accounts receivable, net	2,539.1		2,331.2
Merchandise inventory	525.2		387.4
Miscellaneous receivables	300.6		187.7
Prepaid expenses and other	122.6		93.8
Total current assets	3,487.5		3,000.1
Operating lease right-of-use assets	33.1
Property and equipment, net	68.4		52
Goodwill	1,437.9		1,437.8
Other intangible assets, net	206.2		300
Other assets	2.4		9.6
Investment in and advances to subsidiaries	0		0
Total Assets	5,235.5		4,799.5
Current liabilities:
Accounts payable-trade	1,701.9		1,387.9
Accounts payable-inventory financing	382		406.1
Current maturities of long-term debt	4.2		4
Contract liabilities	127.1		95.6
Accrued expenses and other current liabilities	352		306.7
Total current liabilities	2,567.2		2,200.3
Long-term liabilities:
Debt	0		4.3
Deferred income taxes	32		60.5
Operating lease liabilities	25.2
Other liabilities	0.9		5.7
Total long-term liabilities	58.1		70.5
Total stockholders' equity	2,610.2		2,528.7
Total Liabilities and Stockholders' Equity	5,235.5		4,799.5
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	78.5		46.7
Accounts receivable, net	360.4		340
Merchandise inventory	78.4		66.9
Miscellaneous receivables	28.5		18.1
Prepaid expenses and other	48.3		38.2
Total current assets	594.1		509.9
Operating lease right-of-use assets	27.9
Property and equipment, net	26.9		21.8
Goodwill	326.2		273.2
Other intangible assets, net	166.8		159.7
Other assets	172.1		140.2
Investment in and advances to subsidiaries	0		0
Total Assets	1,314		1,104.8
Current liabilities:
Accounts payable-trade	207.6		166.9
Accounts payable-inventory financing	29.6		23
Current maturities of long-term debt	6.3		6.4
Contract liabilities	85		82.7
Accrued expenses and other current liabilities	83.8		68.8
Total current liabilities	412.3		347.8
Long-term liabilities:
Debt	49.9		57.7
Deferred income taxes	28.7		26.9
Operating lease liabilities	23.5
Other liabilities	220.2		172.2
Total long-term liabilities	322.3		256.8
Total stockholders' equity	579.4		500.2
Total Liabilities and Stockholders' Equity	1,314		1,104.8
Affiliated Entity | Reportable Legal Entities
Current assets:
Cash and cash equivalents	0		0
Accounts receivable, net	0		0
Merchandise inventory	0		0
Miscellaneous receivables	0		0
Prepaid expenses and other	0		0
Total current assets	0		0
Property and equipment, net	0		0
Goodwill	0		0
Other intangible assets, net	0		0
Other assets	0		0
Investment in and advances to subsidiaries	0		0
Total Assets	0		0
Current liabilities:
Accounts payable-trade	0		0
Accounts payable-inventory financing	0		0
Current maturities of long-term debt	0		0
Contract liabilities	0		0
Accrued expenses and other current liabilities	0		0
Total current liabilities	0		0
Long-term liabilities:
Debt	0		0
Deferred income taxes	0		0
Operating lease liabilities	0
Other liabilities	0		0
Total long-term liabilities	0		0
Total stockholders' equity	0		0
Total Liabilities and Stockholders' Equity	$ 0		$ 0

Supplemental Guarantor Inform_4

Supplemental Guarantor Information - Consolidating Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Supplemental Guarantor Information [Line Items]
Net sales	$ 4,907.7	$ 4,373.2	$ 13,495.5	$ 12,165.7
Cost of sales	4,091.2	3,659.6	11,233.1	10,152.6
Gross profit	816.5	713.6	2,262.4	2,013.1
Selling and administrative expenses	444.9	390.7	1,269.3	1,134.8
Advertising expense	51	48.1	143.3	133.9
Operating income	320.6	274.8	849.8	744.4
Interest expense, net	(42.3)	(36.6)	(121.1)	(111.5)
Other (expense) income, net	(17.4)	0.2	(15)	1
Income before income taxes	260.9	238.4	713.7	633.9
Income tax (expense) benefit	(59.2)	(54.7)	(162.5)	(150.2)
Income (Loss) before equity in earnings (loss) of subsidiaries	201.7	183.7	551.2	483.7
Equity in earnings of subsidiaries	0	0	0	0
Net income	201.7	183.7	551.2	483.7
Consolidating Adjustments
Supplemental Guarantor Information [Line Items]
Net sales	0	0	0	0
Cost of sales	0	0	0	0
Gross profit	0	0	0	0
Selling and administrative expenses	0	0	0	0
Advertising expense	0	0	0	0
Operating income	0	0	0	0
Interest expense, net	0	0	0	0
Other (expense) income, net	0	0	0	0
Income before income taxes	0	0	0	0
Income tax (expense) benefit	0	0	0	0
Income (Loss) before equity in earnings (loss) of subsidiaries	0	0	0	0
Equity in earnings of subsidiaries	(467.2)	(416.9)	(1,263.8)	(1,119.7)
Net income	(467.2)	(416.9)	(1,263.8)	(1,119.7)
Parent Guarantor | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net sales	0	0	0	0
Cost of sales	0	0	0	0
Gross profit	0	0	0	0
Selling and administrative expenses	0	0	0	0
Advertising expense	0	0	0	0
Operating income	0	0	0	0
Interest expense, net	0	0	0	0
Other (expense) income, net	0	0	0	0
Income before income taxes	0	0	0	0
Income tax (expense) benefit	(0.1)	(0.1)	(0.3)	(0.3)
Income (Loss) before equity in earnings (loss) of subsidiaries	(0.1)	(0.1)	(0.3)	(0.3)
Equity in earnings of subsidiaries	201.8	183.8	551.5	484
Net income	201.7	183.7	551.2	483.7
Subsidiary Issuer | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net sales	0	0	0	0
Cost of sales	0	0	0	0
Gross profit	0	0	0	0
Selling and administrative expenses	35.8	33.7	99.7	103.3
Advertising expense	0	0	0	0
Operating income	(35.8)	(33.7)	(99.7)	(103.3)
Interest expense, net	(42)	(36.1)	(120.2)	(109.9)
Other (expense) income, net	(16.1)	0	(16.1)	0
Income before income taxes	(93.9)	(69.8)	(236)	(213.2)
Income tax (expense) benefit	30.3	20.5	75.2	61.5
Income (Loss) before equity in earnings (loss) of subsidiaries	(63.6)	(49.3)	(160.8)	(151.7)
Equity in earnings of subsidiaries	265.4	233.1	712.3	635.7
Net income	201.8	183.8	551.5	484
Guarantor Subsidiaries | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net sales	4,400.6	3,921.6	11,924.5	10,743.7
Cost of sales	3,671.5	3,286.6	9,926.3	8,966.6
Gross profit	729.1	635	1,998.2	1,777.1
Selling and administrative expenses	347.4	299.8	980.6	861.8
Advertising expense	47.2	45.9	134.7	128.3
Operating income	334.5	289.3	882.9	787
Interest expense, net	0.1	0.9	0.3	2.8
Other (expense) income, net	0	0.1	2.1	0.6
Income before income taxes	334.6	290.3	885.3	790.4
Income tax (expense) benefit	(87.9)	(75.3)	(229.2)	(202.6)
Income (Loss) before equity in earnings (loss) of subsidiaries	246.7	215	656.1	587.8
Equity in earnings of subsidiaries	0	0	0	0
Net income	246.7	215	656.1	587.8
Non-Guarantor Subsidiaries | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net sales	507.1	451.6	1,571	1,422
Cost of sales	419.7	373	1,306.8	1,186
Gross profit	87.4	78.6	264.2	236
Selling and administrative expenses	61.7	57.2	189	169.7
Advertising expense	3.8	2.2	8.6	5.6
Operating income	21.9	19.2	66.6	60.7
Interest expense, net	(0.4)	(1.4)	(1.2)	(4.4)
Other (expense) income, net	(1.3)	0.1	(1)	0.4
Income before income taxes	20.2	17.9	64.4	56.7
Income tax (expense) benefit	(1.5)	0.2	(8.2)	(8.8)
Income (Loss) before equity in earnings (loss) of subsidiaries	18.7	18.1	56.2	47.9
Equity in earnings of subsidiaries	0	0	0	0
Net income	18.7	18.1	56.2	47.9
Affiliated Entity | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net sales	0	0	0	0
Cost of sales	0	0	0	0
Gross profit	0	0	0	0
Selling and administrative expenses	0	0	0	0
Advertising expense	0	0	0	0
Operating income	0	0	0	0
Interest expense, net	0	0	0	0
Other (expense) income, net	0	0	0	0
Income before income taxes	0	0	0	0
Income tax (expense) benefit	0	0	0	0
Income (Loss) before equity in earnings (loss) of subsidiaries	0	0	0	0
Equity in earnings of subsidiaries	0	0	0	0
Net income	$ 0	$ 0	$ 0	$ 0

Supplemental Guarantor Inform_5

Supplemental Guarantor Information - Condensed Consolidating Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	$ 187	$ 180.6	$ 527.7	$ 471.4
Consolidating Adjustments
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	(437.9)	(410.6)	(1,227.6)	(1,089.5)
Parent Guarantor | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	187	180.6	527.7	471.4
Subsidiary Issuer | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	187.1	180.7	528	471.7
Guarantor Subsidiaries | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	246.7	215	656.1	587.8
Non-Guarantor Subsidiaries | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	4.1	14.9	43.5	30
Affiliated Entity | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Comprehensive income (loss)	$ 0	$ 0	$ 0	$ 0

Supplemental Guarantor Inform_6

Supplemental Guarantor Information - Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	$ 682.3	$ 602.3
Cash flows used in investing activities:
Capital expenditures	(75)	(53.4)
Acquisition of business, net of cash acquired	(75)	0
Net cash used in investing activities	(150)	(53.4)
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	1,860.5	688.9
Repayments of borrowings under revolving credit facility	(1,834.5)	(681.9)
Repayments of long-term debt	(19.7)	(18.2)
Proceeds from Issuance of Long-term Debt	600	0
Payments to extinguish long-term debt	(538.1)	0
Net change in accounts payable-inventory financing	(17.4)	(90.1)
Repurchases of common stock	(493.3)	(232.5)
Payment of incentive compensation plan withholding taxes	(21.3)	(27.1)
Dividend payments	(128.9)	(95.5)
Capital contributions	0	0
Other	24.2	21.1
Distributions and advances from (to) affiliates	0	0
Net cash used in financing activities	(568.5)	(435.3)
Effect of exchange rate changes on cash and cash equivalents	(2.7)	(2.7)
Net (decrease) increase in cash and cash equivalents	(38.9)	110.9
Cash and cash equivalents—beginning of period	205.8	144.2
Cash and cash equivalents—end of period	166.9	255.1
Consolidating Adjustments
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	(27.4)	(7.4)
Cash flows used in investing activities:
Capital expenditures	0	0
Acquisition of business, net of cash acquired	0
Net cash used in investing activities	0	0
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	0	0
Repayments of borrowings under revolving credit facility	0	0
Repayments of long-term debt	0	0
Proceeds from Issuance of Long-term Debt	0
Payments to extinguish long-term debt	0
Net change in accounts payable-inventory financing	0	0
Repurchases of common stock	0	0
Payment of incentive compensation plan withholding taxes	0	0
Dividend payments	0	0
Capital contributions	0	0
Other	0	0
Distributions and advances from (to) affiliates	8.6	(6)
Net cash used in financing activities	8.6	(6)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net (decrease) increase in cash and cash equivalents	(18.8)	(13.4)
Cash and cash equivalents—beginning of period	(16.9)	(1.9)
Cash and cash equivalents—end of period	(35.7)	(15.3)
Reportable Legal Entities
Cash flows used in financing activities:
Proceeds from Issuance of Long-term Debt	0
Payments to extinguish long-term debt	0
Parent Guarantor
Cash flows used in investing activities:
Acquisition of business, net of cash acquired	0
Parent Guarantor | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	0	0
Cash flows used in investing activities:
Capital expenditures	0	0
Net cash used in investing activities	0	0
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	0	0
Repayments of borrowings under revolving credit facility	0	0
Repayments of long-term debt	0	0
Proceeds from Issuance of Long-term Debt	0
Payments to extinguish long-term debt	0
Net change in accounts payable-inventory financing	0	0
Repurchases of common stock	(493.3)	(232.5)
Payment of incentive compensation plan withholding taxes	(21.3)	(27.1)
Dividend payments	(128.9)	(95.5)
Capital contributions	0	0
Other	0	0
Distributions and advances from (to) affiliates	643.5	355.1
Net cash used in financing activities	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Net (decrease) increase in cash and cash equivalents	0	0
Cash and cash equivalents—beginning of period	0	0
Cash and cash equivalents—end of period	0	0
Subsidiary Issuer
Cash flows used in investing activities:
Acquisition of business, net of cash acquired	0
Subsidiary Issuer | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	(6.3)	(78.9)
Cash flows used in investing activities:
Capital expenditures	(46.4)	(40.9)
Net cash used in investing activities	(46.4)	(40.9)
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	1,860.5	640
Repayments of borrowings under revolving credit facility	(1,834.5)	(640)
Repayments of long-term debt	(11)	(11.2)
Proceeds from Issuance of Long-term Debt	600
Payments to extinguish long-term debt	(538.1)
Net change in accounts payable-inventory financing	0	(0.8)
Repurchases of common stock	0	0
Payment of incentive compensation plan withholding taxes	0	0
Dividend payments	0	0
Capital contributions	(76)	0
Other	28.8	25.8
Distributions and advances from (to) affiliates	(28.9)	213.2
Net cash used in financing activities	0.8	227
Effect of exchange rate changes on cash and cash equivalents	0	0
Net (decrease) increase in cash and cash equivalents	(51.9)	107.2
Cash and cash equivalents—beginning of period	176	113.7
Cash and cash equivalents—end of period	124.1	220.9
Guarantor Subsidiaries
Cash flows used in investing activities:
Acquisition of business, net of cash acquired	0
Guarantor Subsidiaries | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	620.6	608.4
Cash flows used in investing activities:
Capital expenditures	(19.5)	(3.5)
Net cash used in investing activities	(19.5)	(3.5)
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	0	0
Repayments of borrowings under revolving credit facility	0	0
Repayments of long-term debt	0	0
Proceeds from Issuance of Long-term Debt	0
Payments to extinguish long-term debt	0
Net change in accounts payable-inventory financing	(24.2)	(85.8)
Repurchases of common stock	0	0
Payment of incentive compensation plan withholding taxes	0	0
Dividend payments	0	0
Capital contributions	0	47.5
Other	(4.4)	(4.3)
Distributions and advances from (to) affiliates	(572.5)	(562.3)
Net cash used in financing activities	(601.1)	(604.9)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net (decrease) increase in cash and cash equivalents	0	0
Cash and cash equivalents—beginning of period	0	0
Cash and cash equivalents—end of period	0	0
Non-Guarantor Subsidiaries
Cash flows used in investing activities:
Acquisition of business, net of cash acquired	(75)
Non-Guarantor Subsidiaries | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	95.4	80.2
Cash flows used in investing activities:
Capital expenditures	(9.1)	(9)
Net cash used in investing activities	(84.1)	(9)
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	0	48.9
Repayments of borrowings under revolving credit facility	0	(41.9)
Repayments of long-term debt	(8.7)	(7)
Proceeds from Issuance of Long-term Debt	0
Payments to extinguish long-term debt	0
Net change in accounts payable-inventory financing	6.8	(3.5)
Repurchases of common stock	0	0
Payment of incentive compensation plan withholding taxes	0	0
Dividend payments	0	0
Capital contributions	76	(47.5)
Other	(0.2)	(0.4)
Distributions and advances from (to) affiliates	(50.7)	0
Net cash used in financing activities	23.2	(51.4)
Effect of exchange rate changes on cash and cash equivalents	(2.7)	(2.7)
Net (decrease) increase in cash and cash equivalents	31.8	17.1
Cash and cash equivalents—beginning of period	46.7	32.4
Cash and cash equivalents—end of period	78.5	49.5
Affiliated Entity
Cash flows used in investing activities:
Acquisition of business, net of cash acquired	0
Affiliated Entity | Reportable Legal Entities
Supplemental Guarantor Information [Line Items]
Net cash provided by operating activities	0	0
Cash flows used in investing activities:
Capital expenditures	0	0
Net cash used in investing activities	0	0
Cash flows used in financing activities:
Proceeds from borrowings under revolving credit facility	0	0
Repayments of borrowings under revolving credit facility	0	0
Repayments of long-term debt	0	0
Net change in accounts payable-inventory financing	0	0
Repurchases of common stock	0	0
Payment of incentive compensation plan withholding taxes	0	0
Dividend payments	0	0
Capital contributions	0	0
Other	0	0
Distributions and advances from (to) affiliates	0	0
Net cash used in financing activities	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Net (decrease) increase in cash and cash equivalents	0	0
Cash and cash equivalents—beginning of period	0	0
Cash and cash equivalents—end of period	$ 0	$ 0