XML 69 R55.htm IDEA: XBRL DOCUMENT
v3.25.2

Loans - Consumer Banking Portfolio by Credit Quality Indicator (Details) - USD ($) $ in Millions | Jun. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | $ 439,297 | $ 327,775
Consumer Banking: |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Term Loans by Vintage Year, Year 1 | 19,300 | 30,886
Term Loans by Vintage Year, Year 2 | 26,145 | 16,785
Term Loans by Vintage Year, Year 3 | 13,594 | 14,819
Term Loans by Vintage Year, Year 4 | 11,435 | 10,202
Term Loans by Vintage Year, Year 5 | 7,354 | 3,408
Prior | 3,047 | 1,623
Total Term Loans | 80,875 | 77,723
Revolving Loans | 355 | 365
Revolving Loans Converted to Term | 3 | 4
Total | 81,233 | 78,092
Auto | Consumer Banking: |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Term Loans by Vintage Year, Year 1 | 19,243 | 30,743
Term Loans by Vintage Year, Year 2 | 26,015 | 16,707
Term Loans by Vintage Year, Year 3 | 13,520 | 14,726
Term Loans by Vintage Year, Year 4 | 11,352 | 10,153
Term Loans by Vintage Year, Year 5 | 7,310 | 3,356
Prior | 2,577 | 1,144
Total Term Loans | 80,017 | 76,829
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Total | 80,017 | 76,829
Retail banking | Consumer Banking: |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Term Loans by Vintage Year, Year 1 | 57 | 143
Term Loans by Vintage Year, Year 2 | 130 | 78
Term Loans by Vintage Year, Year 3 | 74 | 93
Term Loans by Vintage Year, Year 4 | 83 | 49
Term Loans by Vintage Year, Year 5 | 44 | 52
Prior | 470 | 479
Total Term Loans | 858 | 894
Revolving Loans | 355 | 365
Revolving Loans Converted to Term | 3 | 4
Total | 1,216 | 1,263
Current | Retail banking | Consumer Banking: |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Term Loans by Vintage Year, Year 1 | 57 | 143
Term Loans by Vintage Year, Year 2 | 130 | 78
Term Loans by Vintage Year, Year 3 | 74 | 93
Term Loans by Vintage Year, Year 4 | 83 | 49
Term Loans by Vintage Year, Year 5 | 44 | 51
Prior | 466 | 469
Total Term Loans | 854 | 883
Revolving Loans | 343 | 351
Revolving Loans Converted to Term | 3 | 3
Total | 1,200 | 1,237
30-59 days | Retail banking | Consumer Banking: |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Term Loans by Vintage Year, Year 1 | 0 | 0
Term Loans by Vintage Year, Year 2 | 0 | 0
Term Loans by Vintage Year, Year 3 | 0 | 0
Term Loans by Vintage Year, Year 4 | 0 | 0
Term Loans by Vintage Year, Year 5 | 0 | 0
Prior | 3 | 2
Total Term Loans | 3 | 2
Revolving Loans | 8 | 11
Revolving Loans Converted to Term | 0 | 0
Total | 11 | 13
60-89 days | Retail banking | Consumer Banking: |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Term Loans by Vintage Year, Year 1 | 0 | 0
Term Loans by Vintage Year, Year 2 | 0 | 0
Term Loans by Vintage Year, Year 3 | 0 | 0
Term Loans by Vintage Year, Year 4 | 0 | 0
Term Loans by Vintage Year, Year 5 | 0 | 0
Prior | 0 | 1
Total Term Loans | 0 | 1
Revolving Loans | 2 | 2
Revolving Loans Converted to Term | 0 | 0
Total | 2 | 3
Greater than 90 days | Retail banking | Consumer Banking: |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Term Loans by Vintage Year, Year 1 | 0 | 0
Term Loans by Vintage Year, Year 2 | 0 | 0
Term Loans by Vintage Year, Year 3 | 0 | 0
Term Loans by Vintage Year, Year 4 | 0 | 0
Term Loans by Vintage Year, Year 5 | 0 | 1
Prior | 1 | 7
Total Term Loans | 1 | 8
Revolving Loans | 2 | 1
Revolving Loans Converted to Term | 0 | 1
Total | 3 | 10
Greater than 660 | Auto | Consumer Banking: |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Term Loans by Vintage Year, Year 1 | 9,274 | 17,057
Term Loans by Vintage Year, Year 2 | 14,173 | 8,333
Term Loans by Vintage Year, Year 3 | 6,668 | 8,194
Term Loans by Vintage Year, Year 4 | 6,285 | 5,621
Term Loans by Vintage Year, Year 5 | 4,022 | 1,482
Prior | 1,040 | 394
Total Term Loans | 41,462 | 41,081
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Total | 41,462 | 41,081
621-660 | Auto | Consumer Banking: |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Term Loans by Vintage Year, Year 1 | 3,466 | 5,584
Term Loans by Vintage Year, Year 2 | 4,790 | 3,492
Term Loans by Vintage Year, Year 3 | 2,846 | 2,906
Term Loans by Vintage Year, Year 4 | 2,253 | 1,986
Term Loans by Vintage Year, Year 5 | 1,436 | 667
Prior | 517 | 235
Total Term Loans | 15,308 | 14,870
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Total | 15,308 | 14,870
620 or below | Auto | Consumer Banking: |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Term Loans by Vintage Year, Year 1 | 6,503 | 8,102
Term Loans by Vintage Year, Year 2 | 7,052 | 4,882
Term Loans by Vintage Year, Year 3 | 4,006 | 3,626
Term Loans by Vintage Year, Year 4 | 2,814 | 2,546
Term Loans by Vintage Year, Year 5 | 1,852 | 1,207
Prior | 1,020 | 515
Total Term Loans | 23,247 | 20,878
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Total | $ 23,247 | $ 20,878

X
- Definition Financing Receivable, Excluding Accrued Interest, Before Allowance for Credit Loss, Term Loans + References No definition available. + Details
Name: | cof_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossTermLoans
Namespace Prefix: | cof_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-5 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, of financing receivable originated more than five years prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-79 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, of financing receivable that can be withdrawn, repaid, and redrawn. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-79 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestRevolving
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, of revolving financing receivable converted to term loan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-79 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6A -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6A Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, of financing receivable originated four years prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-79 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-79 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, of financing receivable originated in current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-79 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, of financing receivable originated two years prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-79 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest of financing receivable originated in fiscal year prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-79 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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 Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 15 -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-15 Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-5 Reference 11: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 15 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-15 Reference 12: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 13: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 14: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (e)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 15: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (e)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 16: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 17: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 18: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 19: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 15 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-15 Reference 20: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 15 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-15 Reference 21: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 15 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-15 Reference 22: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 29 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-29 Reference 23: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-79 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_AutomobileLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cof_RetailBankingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=cof_FinancialAssetCurrentAndLessThan30DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables30To59DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables60To89DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditScoreFicoAxis=cof_FICOScoreGreaterThan660Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditScoreFicoAxis=cof_FICOScore621To660Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditScoreFicoAxis=cof_FICOScoreLessThan620Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |