XML 56 R40.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Description of Business and Summary of Significant Accounting Policies - Additional Information (Details) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 USD ($) subsidiary | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($)
Accounting Policies [Abstract] |  |  |
Number of owned subsidiaries | subsidiary | 2 |  |
Accounts receivable, sale | $ 506 | $ 539 |
Quantitative impairment test frequency | 3 years |  |
Years forecasted in goodwill impairment income approach | 5 years |  |
Advertising expense | $ 215 | $ 211 | $ 199

X
- Definition Forecasted Years for Goodwill Impairment + References No definition available. + Details
Name: | cdw_ForecastedYearsforGoodwillImpairment
Namespace Prefix: | cdw_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Goodwill, Quantitative Impairment Test Frequency + References No definition available. + Details
Name: | cdw_GoodwillQuantitativeImpairmentTestFrequency
Namespace Prefix: | cdw_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Owned Subsidiaries + References No definition available. + Details
Name: | cdw_NumberofOwnedSubsidiaries
Namespace Prefix: | cdw_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of decrease from sale of accounts receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (i) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-11 + Details
Name: | us-gaap_AccountsReceivableSale
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 720 -SubTopic 35 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483406/720-35-50-1 + Details
Name: | us-gaap_AdvertisingExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration