XML 98 R87.htm IDEA: XBRL DOCUMENT
v3.20.2

Commitments, Contingencies, Guarantees, and Others - Litigation (Detail) $ in Millions | 1 Months Ended | 6 Months Ended
--- | --- | ---
Oct. 31, 2018 USD ($) | Jun. 30, 2020 USD ($) claim
Loss Contingencies [Line Items] |  |
Loss contingency, estimate of possible loss |  | $ 1,000
Anti-money laundering |  |
Loss Contingencies [Line Items] |  |
Litigation settlement paid | $ 100 |
Cybersecurity Incident [Member] |  |
Loss Contingencies [Line Items] |  |
Number of consumer class action cases filed for Cybersecurity Incident | claim |  | 73
Penalty to the US Treasury Accrued |  | $ 80
Pending litigation | Interchange litigation |  |
Loss Contingencies [Line Items] |  |
Litigation settlement, attributable to reporting entity and third party |  | $ 5,500
United States | Cybersecurity Incident [Member] |  |
Loss Contingencies [Line Items] |  |
Number of consumer class action cases filed for Cybersecurity Incident | claim |  | 61
Canada | Cybersecurity Incident [Member] |  |
Loss Contingencies [Line Items] |  |
Number of consumer class action cases filed for Cybersecurity Incident | claim |  | 12

X
- Definition Litigation Settlement, Amount Attributable to Reporting Entity and Third Party + References No definition available. + Details
Name: | cof_LitigationSettlementAmountAttributabletoReportingEntityandThirdParty
Namespace Prefix: | cof_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of consumer class action cases filed for Cybersecurity Incident + References No definition available. + Details
Name: | cof_NumberofConsumerClassActionCasesFiledforCybersecurityIncident
Namespace Prefix: | cof_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Penalty to the US Treasury Accrued + References No definition available. + Details
Name: | cof_PenaltytotheUSTreasuryAccrued
Namespace Prefix: | cof_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount awarded to other party in judgment or settlement of litigation. + References No definition available. + Details
Name: | us-gaap_LitigationSettlementAmountAwardedToOtherParty
Namespace Prefix: | us-gaap_
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_LossContingenciesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reflects the estimated amount of loss from the specified contingency as of the balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 9 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12021-110248 + Details
Name: | us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | srt_LitigationCaseAxis=cof_AntiMoneyLaunderingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_LitigationCaseAxis=cof_CybersecurityIncidentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LitigationStatusAxis=us-gaap_PendingLitigationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_LitigationCaseAxis=cof_InterchangeLitigationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_CA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |