Allowance for Credit Losses and Reserve for Unfunded Lending Commitments - Charge-Offs (Details) $ in Millions	6 Months Ended
Jun. 30, 2023 USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
2023	$ 15
2022	375
2021	388
2020	189
2019	194
Prior	251
Total Term Loans	1,412
Revolving Loans	3,562
Revolving Loans Converted to Term	41
Total	5,015
Credit Card:
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	3,515
Revolving Loans Converted to Term	41
Total	3,556
Credit Card: \| Domestic Card
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	3,310
Revolving Loans Converted to Term	35
Total	3,345
Credit Card: \| International card businesses
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving Loans	205
Revolving Loans Converted to Term	6
Total	211
Consumer Banking:
Financing Receivable, Credit Quality Indicator [Line Items]
2023	13
2022	344
2021	342
2020	167
2019	96
Prior	63
Total Term Loans	1,025
Revolving Loans	32
Revolving Loans Converted to Term	0
Total	1,057
Consumer Banking: \| Auto
Financing Receivable, Credit Quality Indicator [Line Items]
2023	13
2022	344
2021	341
2020	167
2019	96
Prior	63
Total Term Loans	1,024
Revolving Loans	0
Revolving Loans Converted to Term	0
Total	1,024
Consumer Banking: \| Retail banking
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	0
2021	1
2020	0
2019	0
Prior	0
Total Term Loans	1
Revolving Loans	32
Revolving Loans Converted to Term	0
Total	33
Commercial Portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
2023	2
2022	31
2021	46
2020	22
2019	98
Prior	188
Total Term Loans	387
Revolving Loans	15
Revolving Loans Converted to Term	0
Total	402
Commercial Portfolio \| Commercial and multifamily real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	29
2021	46
2020	22
2019	98
Prior	185
Total Term Loans	380
Revolving Loans	0
Revolving Loans Converted to Term	0
Total	380
Commercial Portfolio \| Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
2023	2
2022	2
2021	0
2020	0
2019	0
Prior	3
Total Term Loans	7
Revolving Loans	15
Revolving Loans Converted to Term	0
Total	$ 22

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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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
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