Amount owed under Revolving loan financing agreement

No definition available.

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- Definition

Cash Availability, Percentage of Borrowing Base

+ References

No definition available.

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- Definition

For an unclassified balance sheet, the carrying amount (net of accumulated amortization) as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) and premiums that will be charged against earnings over the life of the debt instruments to which such costs and premiums pertain.

+ References

No definition available.

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- Definition

Fixed Charge Coverage Ratio

+ References

No definition available.

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- Definition

Line of Credit Facility, Borrowing Base

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Minimum Liquidity Condition, Amount

+ References

No definition available.

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- Definition

Minimum Liquidity Condition, Cash Availability

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: 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 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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-Publisher FASB
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-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Long-Term Debt - Revolving Loan (Details) £ in Millions	3 Months Ended
Long-Term Debt - Revolving Loan (Details) £ in Millions	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2018 GBP (£)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Carrying value				$ 3,255,000,000	$ 3,255,900,000
Net loss on extinguishments of long-term debt	$ 0	$ 57,400,000
CDW UK term loan
Debt Instrument [Line Items]
Carrying value			£ 56	78,500,000	75,700,000
Deferred finance costs, net and unamortized premium			£ 1	1,000,000
Senior secured asset-based revolving credit facility
Debt Instrument [Line Items]
Carrying value				0	$ 0
Undrawn letters of credit				1,000,000
Borrowing base				1,600,000,000
Additional borrowing capacity				987,000,000
Cash availability, minimum liquidity				$ 125,000,000
Cash availability, percentage of borrowing base			10.00%	10.00%
Minimum liquidity, amount				$ 100,000,000
Basis spread on variable rate (as percent)	1.00%
Net loss on extinguishments of long-term debt		1,000,000
Deferred finance costs, net and unamortized premium		$ 4,000,000
Minimum \| Senior secured asset-based revolving credit facility
Debt Instrument [Line Items]
Consolidated fixed charge coverage ratio			1.00	1.00
Federal Funds Effective Swap Rate \| Senior secured asset-based revolving credit facility
Debt Instrument [Line Items]
Basis spread on variable rate (as percent)	0.50%
London Interbank Offered Rate (LIBOR) \| Minimum \| Senior secured asset-based revolving credit facility
Debt Instrument [Line Items]
Basis spread on variable rate (as percent)	1.25%
London Interbank Offered Rate (LIBOR) \| Maximum \| Senior secured asset-based revolving credit facility
Debt Instrument [Line Items]
Basis spread on variable rate (as percent)	1.75%
Base Rate \| Minimum \| Senior secured asset-based revolving credit facility
Debt Instrument [Line Items]
Basis spread on variable rate (as percent)	0.25%
Base Rate \| Maximum \| Senior secured asset-based revolving credit facility
Debt Instrument [Line Items]
Basis spread on variable rate (as percent)	0.75%
Accounts Payable, Inventory Financing \| Senior secured asset-based revolving credit facility
Debt Instrument [Line Items]
Amount owed under Revolving loan financing agreement				$ 462,000,000