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Income Taxes Deferred Tax Assets and Liabilities (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2014
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Dec. 31, 2013
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| Deferred Tax Assets, Gross [Abstract] | ||
| Deferred interest | $ 32.9cdw_DeferredTaxAssetsDeferredInterest | $ 43.5cdw_DeferredTaxAssetsDeferredInterest |
| State net operating loss and credit carryforwards, net | 18.8us-gaap_DeferredTaxAssetsOperatingLossCarryforwards | 21.1us-gaap_DeferredTaxAssetsOperatingLossCarryforwards |
| Payroll and benefits | 27.0us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits | 16.2us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits |
| Deferred Tax Assets, Rent | 5.5cdw_DeferredTaxAssetsRent | 6.4cdw_DeferredTaxAssetsRent |
| Accounts receivable | 6.3us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts | 5.4us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts |
| Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost | 6.5us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost | 1.6us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost |
| Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Other | 1.5us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther | 1.5us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther |
| Other | 5.0us-gaap_DeferredTaxAssetsOther | 7.1us-gaap_DeferredTaxAssetsOther |
| Total deferred tax assets | 103.5us-gaap_DeferredTaxAssetsGross | 102.8us-gaap_DeferredTaxAssetsGross |
| Deferred Tax Liabilities, Gross [Abstract] | ||
| Software and intangibles | 425.3us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets | 486.2us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets |
| Deferred Income | 116.2us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome | 145.5us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome |
| Property and equipment | 22.5us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment | 25.0us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment |
| Other | 15.3us-gaap_DeferredTaxLiabilitiesOther | 11.6us-gaap_DeferredTaxLiabilitiesOther |
| Total deferred tax liabilites | 579.3us-gaap_DeferredIncomeTaxLiabilities | 668.3us-gaap_DeferredIncomeTaxLiabilities |
| Deferred tax assets valuation allowance | 0us-gaap_DeferredTaxAssetsValuationAllowance | 0us-gaap_DeferredTaxAssetsValuationAllowance |
| Net deferred tax liabilities | 475.8us-gaap_DeferredTaxLiabilities | 565.5us-gaap_DeferredTaxLiabilities |
| Operating Loss Carryforwards [Line Items] | ||
| Undistributed Earnings of Foreign Subsidiaries | 66.6us-gaap_UndistributedEarningsOfForeignSubsidiaries | |
| State and Local Jurisdiction [Member] | ||
| Operating Loss Carryforwards [Line Items] | ||
| Operating Loss Carryforwards | 124.0us-gaap_OperatingLossCarryforwards / us-gaap_IncomeTaxAuthorityAxis = us-gaap_StateAndLocalJurisdictionMember |
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| Tax Credit Carryforward, Amount | $ 19.6us-gaap_TaxCreditCarryforwardAmount / us-gaap_IncomeTaxAuthorityAxis = us-gaap_StateAndLocalJurisdictionMember |
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- Definition
Deferred Tax Assets, Deferred Interest No definition available.
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- Definition
Deferred Tax Assets, Rent No definition available.
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- Definition
Amount of deferred tax liability attributable to taxable temporary differences. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences not separately disclosed. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensation and benefits costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from the allowance for doubtful accounts. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from other reserves and accruals not separately disclosed. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of deferred tax liability attributable to taxable temporary differences net of deferred tax asset attributable to deductible temporary differences and carryforwards after valuation allowances. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of deferred tax liability attributable to taxable temporary differences not separately disclosed. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of deferred tax liability attributable to taxable temporary differences from tax deferred revenue or other income not separately disclosed. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of undistributed earnings of foreign subsidiaries intended to be permanently reinvested outside the country of domicile. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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