Amount owed under Revolving loan financing agreement

No definition available.

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Namespace Prefix:	cdw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility, Borrowing Base

+ References

No definition available.

+ Details

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

- Definition

Amount of restricted net assets of consolidated and unconsolidated subsidiaries as of the end of the most recently completed fiscal year.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.4-08.(e)(3)(ii))
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Balance Type:	debit
Period Type:	instant

- 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/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
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+ Details

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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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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of the required periodic payments applied to principal.

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

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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-Publisher FASB
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Balance Type:	na
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

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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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).

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-Name Accounting Standards Codification
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted average interest rate of long-term debt outstanding calculated at point in time.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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-Subparagraph (b)
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Balance Type:	credit
Period Type:	duration

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Long-Term Debt - Narrative (Details) $ in Millions	9 Months Ended		12 Months Ended
Long-Term Debt - Narrative (Details) $ in Millions	Sep. 30, 2019 GBP (£)	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2019 USD ($)
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				1,700.0
Periodic payment, principal		$ 4.0
Long-term debt			$ 1,453.2	$ 1,442.0
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	$ 6.0
Amount of restricted payment capacity under the loan	£ 134,000,000			$ 165.0
Long-term debt			$ 65.0	$ 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			$ 61.0
Long-term debt			$ 0.0	$ 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				$ 1.0
Borrowing base				2,200.0
Additional borrowing capacity				1,100.0
Long-term debt			$ 0.0	$ 26.0
Interest rate in effect	3.31%		0.00%	3.31%
Senior notes due 2025
Debt Instrument [Line Items]
Long-term debt			$ 600.0	$ 600.0
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			$ 0.0	$ 600.0
Interest rate in effect	4.25%		0.00%	4.25%
Senior notes due 2023
Debt Instrument [Line Items]
Long-term debt			$ 525.0	$ 0.0
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				$ 356.0