Loans - Consumer, Excluding Credit Card Loan Portfolio, Impaired Loans (Details) - Consumer, excluding credit card $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) payment	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Impaired loans
Loans modified subsequent to repurchase from Ginnie Mae	$ 16		$ 16		$ 4,100
TDRs less than 90 days past due	1,900		1,900		2,000
Total residential real estate – excluding PCI
Impaired loans
With an allowance	4,020		4,020		4,523
Without an allowance	2,059		2,059		2,054
Total impaired loans	6,079		6,079		6,577
Allowance for loan losses related to impaired loans	77		77		133
Unpaid principal balance of impaired loans	8,933		8,933		9,673
Impaired loans on nonaccrual status	2,357		2,357		2,414
Average impaired loans	6,138	$ 6,937	6,363	$ 7,334
Interest income on impaired loans	88	94	270	295
Interest income on impaired loans on a cash basis	38	40	$ 114	121
Number of payments under modified terms to recognize interest on cash basis \| payment			6
Residential mortgage
Impaired loans
With an allowance	2,958		$ 2,958		3,381
Without an allowance	1,160		1,160		1,184
Total impaired loans	4,118		4,118		4,565
Allowance for loan losses related to impaired loans	63		63		88
Unpaid principal balance of impaired loans	5,578		5,578		6,207
Impaired loans on nonaccrual status	1,376		1,376		1,459
Average impaired loans	4,200	4,872	4,390	5,242
Interest income on impaired loans	55	61	171	197
Interest income on impaired loans on a cash basis	17	19	$ 52	58
Residential mortgage \| Permanent Modification
Impaired loans
Rate of default for modified loans, estimated weighted average			12.00%
Home equity
Impaired loans
With an allowance	1,062		$ 1,062		1,142
Without an allowance	899		899		870
Total impaired loans	1,961		1,961		2,012
Allowance for loan losses related to impaired loans	14		14		45
Unpaid principal balance of impaired loans	3,355		3,355		3,466
Impaired loans on nonaccrual status	981		981		$ 955
Average impaired loans	1,938	2,065	1,973	2,092
Interest income on impaired loans	33	33	99	98
Interest income on impaired loans on a cash basis	$ 21	$ 21	$ 62	$ 63
Home equity \| Permanent Modification
Impaired loans
Rate of default for modified loans, estimated weighted average			7.00%

Impaired Financing Receivable, Recorded Investment, Nonaccrual Status

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Represents the carrying amount of loans with terms that have been modified in trouble debt restructurings that have not yet made six payments under the modified terms.

+ References

No definition available.

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- Definition

Loans that are repurchased from US government agencies, such as the Government National Mortgage Association (GNMA or Ginnie Mae), and modified subsequent to repurchase. These loans are excluded from loans accounted for as troubled debt restructurings.

+ References

No definition available.

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- Definition

For loans modified in TDRs, the number of borrower payments under the modified terms to generally be recognized as interest income on a cash basis.

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This item represents the estimated weighted average default rate for modified loans.

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- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5258-111524

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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Section 50
-Paragraph 14A
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Amount of allowance for credit losses related to recorded investment.

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Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

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Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

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Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

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