Loans - TDR - Subsequent Defaults (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) contract	Dec. 31, 2021 USD ($) contract	Dec. 31, 2020 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	127,569	86,472	96,905
Total Loans | $	$ 523	$ 428	$ 414
Credit Card
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	111,461	77,608	91,002
Total Loans | $	$ 154	$ 122	$ 156
Consumer Banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	16,101	8,856	5,887
Total Loans | $	$ 286	$ 136	$ 78
Consumer Banking | Auto
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	16,100	8,847	5,877
Total Loans | $	$ 285	$ 136	$ 77
Consumer Banking | Retail banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	1	9	10
Total Loans | $	$ 1	$ 0	$ 1
Commercial Banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	7	8	16
Total Loans | $	$ 83	$ 170	$ 180
Commercial Banking | Commercial And Industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	5	7	15
Total Loans | $	$ 56	$ 120	$ 130
Commercial Banking | Commercial and multifamily real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	2	1	1
Total Loans | $	$ 27	$ 50	$ 50
Domestic credit card: | Credit Card
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	37,029	18,694	32,639
Total Loans | $	$ 75	$ 35	$ 69
International card businesses: | Credit Card
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | contract	74,432	58,914	58,363
Total Loans | $	$ 79	$ 87	$ 87