v2.4.0.8

Inventory Financing Agreements (Details) (USD $) In Millions, unless otherwise specified | Sep. 30, 2014 | Dec. 31, 2013
--- | --- | ---
Inventory Financing Agreements [Line Items] |  |
Accounts payable-inventory financing | $ 299.7 | $ 256.6
Accounts Payable, Inventory Financing [Member] |  |
Inventory Financing Agreements [Line Items] |  |
Revolving Loan inventory financing agreement | 298.8 | 256.1
Other inventory financing agreements | 0.9 | 0.5
Accounts payable-inventory financing | 299.7 | 256.6
Previous Revolving Credit Facility [Member] | Accounts Payable, Inventory Financing [Member] |  |
Inventory Financing Agreements [Line Items] |  |
Floorplan sub-facility | $ 400.0 |

X
- Definition Accounts payable inventory financing. + References No definition available. + Details
Name: | cdw_AccountsPayableInventoryFinancing
Namespace Prefix: | cdw_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Floorplan sub-facility + References No definition available. + Details
Name: | cdw_FloorplanSubFacility
Namespace Prefix: | cdw_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | cdw_InventoryFinancingAgreementsLineItems
Namespace Prefix: | cdw_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Other inventory financing agreements + References No definition available. + Details
Name: | cdw_OtherInventoryFinancingAgreements
Namespace Prefix: | cdw_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Revolving Loan financing agreement + References No definition available. + Details
Name: | cdw_RevolvingLoanFinancingAgreement
Namespace Prefix: | cdw_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant