XML 134 R117.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Fair Value Measurement - Nonrecurring Fair Value Measurements Included in Earnings (Details) - Nonrecurring - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Loans held for investment | $ 2 | $ 198
Other assets | (72) | (85)
Total | $ (70) | $ 113

X
- Definition Gain (Loss) On Fair Value Assets measured on nonrecurring basis + References No definition available. + Details
Name: | cof_GainLossOnFairValueAssetsRecognizedInEarnings
Namespace Prefix: | cof_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gain (Loss) On Fair Value Loans Held For Investment measured on nonrecurring basis + References No definition available. + Details
Name: | cof_GainLossOnFairValueLoansHeldForInvestmentRecognizedInEarnings
Namespace Prefix: | cof_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gain (Loss) On Fair Value Other Assets measured on nonrecurring basis + References No definition available. + Details
Name: | cof_GainLossOnFairValueOtherAssetsRecognizedInEarnings
Namespace Prefix: | cof_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- 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
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |