v2.4.1.9

Long-Term Debt Term Loan (Details) (USD $) | 12 Months Ended | 1 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Jul. 31, 2013 | Apr. 30, 2013 | Sep. 30, 2013 | Apr. 29, 2013 | Mar. 31, 2015
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Proceeds from issuance of long-term debt | $ 1,175,000,000 us-gaap_ProceedsFromIssuanceOfLongTermDebt |  | $ 1,535,200,000 us-gaap_ProceedsFromIssuanceOfLongTermDebt | $ 135,700,000 us-gaap_ProceedsFromIssuanceOfLongTermDebt |  |  |  |  |
Deferred financing costs, net | 33,000,000 us-gaap_DeferredFinanceCostsNoncurrentNet |  | 30,100,000 us-gaap_DeferredFinanceCostsNoncurrentNet | 53,200,000 us-gaap_DeferredFinanceCostsNoncurrentNet |  |  |  |  |
Debt, long-term and short-term | 3,192,400,000 us-gaap_DebtInstrumentCarryingAmount |  |  |  |  |  |  |  |
Gains (Losses) on Extinguishment of Debt | 90,700,000 us-gaap_GainsLossesOnExtinguishmentOfDebt |  | 64,000,000 us-gaap_GainsLossesOnExtinguishmentOfDebt | 17,200,000 us-gaap_GainsLossesOnExtinguishmentOfDebt |  |  |  |  |
Write off of Deferred Debt Issuance Cost | 12,600,000 us-gaap_WriteOffOfDeferredDebtIssuanceCost |  | 20,100,000 us-gaap_WriteOffOfDeferredDebtIssuanceCost |  |  |  |  |  |
Revolving Credit Facility [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Line of Credit Facility, Fee on Unused Portion, Basis Points | 25 cdw_LineOfCreditFacilityFeeOnUnusedPortionBasisPoints / us-gaap_LongtermDebtTypeAxis = us-gaap_RevolvingCreditFacilityMember |  |  |  |  |  |  |  |
Deferred financing costs, net | 6,400,000 us-gaap_DeferredFinanceCostsNoncurrentNet / us-gaap_LongtermDebtTypeAxis = us-gaap_RevolvingCreditFacilityMember |  |  |  |  |  |  |  |
Debt, long-term and short-term | 0 us-gaap_DebtInstrumentCarryingAmount / us-gaap_LongtermDebtTypeAxis = us-gaap_RevolvingCreditFacilityMember |  | 0 us-gaap_DebtInstrumentCarryingAmount / us-gaap_LongtermDebtTypeAxis = us-gaap_RevolvingCreditFacilityMember |  |  |  |  |  |
Long-term Debt, Weighted Average Interest Rate | 0.00%us-gaap_LongtermDebtWeightedAverageInterestRate / us-gaap_LongtermDebtTypeAxis = us-gaap_RevolvingCreditFacilityMember | [1] |  |  |  |  |  |  |
Gains (Losses) on Extinguishment of Debt | 400,000 us-gaap_GainsLossesOnExtinguishmentOfDebt / us-gaap_LongtermDebtTypeAxis = us-gaap_RevolvingCreditFacilityMember |  |  |  |  |  |  |  |
Term Loan [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Proceeds from issuance of long-term debt |  |  |  |  |  | 1,350,000,000 us-gaap_ProceedsFromIssuanceOfLongTermDebt / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  |  |
Discount, percent of par |  |  |  |  | 99.25%cdw_DiscountPercentOfPar / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  |  | 99.75%cdw_DiscountPercentOfPar / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |
Debt Instrument, Unamortized Discount | (3,700,000)us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  | (4,400,000)us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  | 1,400,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  |  | 3,400,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |
Deferred Finance Costs, Net |  |  |  |  | 6,100,000 us-gaap_DeferredFinanceCostsNet / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  |  |  |
Debt, long-term and short-term | 1,513,500,000 us-gaap_DebtInstrumentCarryingAmount / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  | 1,528,900,000 us-gaap_DebtInstrumentCarryingAmount / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  |  |  |  |  |
Long-term Debt, Weighted Average Interest Rate | 3.25%us-gaap_LongtermDebtWeightedAverageInterestRate / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember | [1] |  |  |  |  |  |  |
Gains (Losses) on Extinguishment of Debt |  |  | 10,300,000 us-gaap_GainsLossesOnExtinguishmentOfDebt / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  | 190,000,000 us-gaap_ProceedsFromIssuanceOfDebt / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  |  |  |
Net leverage ratio | 3.1 cdw_NetLeverageRatio / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  |  |  |  |  |  |  |
Quarterly amortization payment of original principal, Percent | 0.25%cdw_QuarterlyAmortizationPaymentOfOriginalPrincipalPercent / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  |  |  |  |  |  |  |
Term Loan [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Long-term Debt, Weighted Average Interest Rate | 3.25%us-gaap_LongtermDebtWeightedAverageInterestRate / cdw_InterestRateBasisAxis = cdw_LiborMember / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember |  |  |  |  |  |  |  |
Prior Term Loan Facility [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Debt, long-term and short-term |  |  |  |  |  |  |  | 1,299,500,000 us-gaap_DebtInstrumentCarryingAmount / us-gaap_LongtermDebtTypeAxis = cdw_PriorTermLoanFacilityMember |
Term Loan, Repayments |  |  |  |  |  |  | 40,000,000 us-gaap_RepaymentsOfDebt / us-gaap_LongtermDebtTypeAxis = cdw_PriorTermLoanFacilityMember |  |
Minimum [Member] | Revolving Credit Facility [Member] | ABR [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Variable Interest Rate Margin | 0.50%cdw_VariableInterestRateMargin / cdw_InterestRateBasisAxis = cdw_AbrMember / us-gaap_LongtermDebtTypeAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |  |  |  |  |
Minimum [Member] | Revolving Credit Facility [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Variable Interest Rate Margin | 1.50%cdw_VariableInterestRateMargin / cdw_InterestRateBasisAxis = cdw_LiborMember / us-gaap_LongtermDebtTypeAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |  |  |  |  |
Minimum [Member] | Term Loan [Member] | ABR [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Variable Interest Rate Margin | 1.25%cdw_VariableInterestRateMargin / cdw_InterestRateBasisAxis = cdw_AbrMember / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |  |  |  |  |
Minimum [Member] | Term Loan [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Variable Interest Rate Margin | 2.25%cdw_VariableInterestRateMargin / cdw_InterestRateBasisAxis = cdw_LiborMember / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |  |  |  |  |
Reference Interest Rate Floor | 1.00%cdw_ReferenceInterestRateFloor / cdw_InterestRateBasisAxis = cdw_LiborMember / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |  |  |  |  |
Maximum [Member] | Revolving Credit Facility [Member] | ABR [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Variable Interest Rate Margin | 1.00%cdw_VariableInterestRateMargin / cdw_InterestRateBasisAxis = cdw_AbrMember / us-gaap_LongtermDebtTypeAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |
Maximum [Member] | Revolving Credit Facility [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Variable Interest Rate Margin | 2.00%cdw_VariableInterestRateMargin / cdw_InterestRateBasisAxis = cdw_LiborMember / us-gaap_LongtermDebtTypeAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |
Maximum [Member] | Term Loan [Member] | ABR [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Variable Interest Rate Margin | 1.50%cdw_VariableInterestRateMargin / cdw_InterestRateBasisAxis = cdw_AbrMember / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |
Maximum [Member] | Term Loan [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Variable Interest Rate Margin | 2.50%cdw_VariableInterestRateMargin / cdw_InterestRateBasisAxis = cdw_LiborMember / us-gaap_LongtermDebtTypeAxis = cdw_TermLoanMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |
Cap agreement effective January 14, 2013-2015 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Derivative, Notional Amount | 1,150,000,000 invest_DerivativeNotionalAmount / us-gaap_DerivativeByNatureAxis = cdw_CapAgreementEffectiveJanuary1420132015Member |  |  |  |  |  |  |  |
Derivative, Cap Interest Rate | 2.40%us-gaap_DerivativeCapInterestRate / us-gaap_DerivativeByNatureAxis = cdw_CapAgreementEffectiveJanuary1420132015Member |  |  |  |  |  |  |  |
Derivative Asset, Noncurrent | 0 us-gaap_DerivativeAssetsNoncurrent / us-gaap_DerivativeByNatureAxis = cdw_CapAgreementEffectiveJanuary1420132015Member |  |  |  |  |  |  |  |
Cap agreement effective January 14, 2015-2017 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Derivative, Notional Amount | 1,000,000,000 invest_DerivativeNotionalAmount / us-gaap_DerivativeByNatureAxis = cdw_CapagreementeffectiveJanuary1420152017Member |  |  |  |  |  |  |  |
Derivative Asset, Noncurrent | 1,700,000 us-gaap_DerivativeAssetsNoncurrent / us-gaap_DerivativeByNatureAxis = cdw_CapagreementeffectiveJanuary1420152017Member |  |  |  |  |  |  |  |
Subsequent Event [Member] | Cap agreement effective January 14, 2015-2017 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Derivative, Notional Amount |  |  |  |  |  |  |  |  | $ 400,000,000 invest_DerivativeNotionalAmount / us-gaap_DerivativeByNatureAxis = cdw_CapagreementeffectiveJanuary1420152017Member / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
Derivative, Cap Interest Rate |  |  |  |  |  |  |  |  | 2.00%us-gaap_DerivativeCapInterestRate / us-gaap_DerivativeByNatureAxis = cdw_CapagreementeffectiveJanuary1420152017Member / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
[1] | Interest rate at December 31, 2014.

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- Definition Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 + Details
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