Allowance for Credit Losses and Reserve for Unfunded Lending Commitments - Charge-Offs (Details) $ in Millions	12 Months Ended
Dec. 31, 2023 USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
2023	$ 143
2022	822
2021	772
2020	349
2019	398
Prior	341
Total Term Loans	2,825
Revolving Loans	7,775
Revolving Loans Converted to Term	102
Total	10,702
Credit Card:
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	7,686
Revolving Loans Converted to Term	101
Total	7,787
Credit Card: \| Domestic Card
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	7,261
Revolving Loans Converted to Term	87
Total	7,348
Credit Card: \| International card businesses
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	425
Revolving Loans Converted to Term	14
Total	439
Consumer Banking:
Financing Receivable, Credit Quality Indicator [Line Items]
2023	141
2022	780
2021	712
2020	327
2019	183
Prior	111
Total Term Loans	2,254
Revolving Loans	72
Revolving Loans Converted to Term	1
Total	2,327
Consumer Banking: \| Auto
Financing Receivable, Credit Quality Indicator [Line Items]
2023	141
2022	780
2021	710
2020	327
2019	183
Prior	111
Total Term Loans	2,252
Revolving Loans	0
Revolving Loans Converted to Term	0
Total	2,252
Consumer Banking: \| Retail banking
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	0
2021	2
2020	0
2019	0
Prior	0
Total Term Loans	2
Revolving Loans	72
Revolving Loans Converted to Term	1
Total	75
Commercial Banking:
Financing Receivable, Credit Quality Indicator [Line Items]
2023	2
2022	42
2021	60
2020	22
2019	215
Prior	230
Total Term Loans	571
Revolving Loans	17
Revolving Loans Converted to Term	0
Total	588
Commercial Banking: \| Commercial and multifamily real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	33
2021	60
2020	22
2019	158
Prior	219
Total Term Loans	492
Revolving Loans	0
Revolving Loans Converted to Term	0
Total	492
Commercial Banking: \| Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
2023	2
2022	9
2021	0
2020	0
2019	57
Prior	11
Total Term Loans	79
Revolving Loans	17
Revolving Loans Converted to Term	0
Total	$ 96

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Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

+ References

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-Topic 326
-SubTopic 20
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