Loans - Schedule of Debtor Troubled Debt Restructuring, Subsequent Periods (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount		$ 523	$ 428
Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	$ 457
Interest rate reduction | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	109
Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	112
Interest Rate Reduction and Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	236
Credit Card:
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount		154	122
Credit Card: | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	110
Credit Card: | Interest rate reduction | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	109
Credit Card: | Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	0
Credit Card: | Interest Rate Reduction and Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	1
Credit Card: | Domestic credit card:
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount		75	35
Credit Card: | Domestic credit card: | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	90
Credit Card: | Domestic credit card: | Interest rate reduction | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	89
Credit Card: | Domestic credit card: | Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	0
Credit Card: | Domestic credit card: | Interest Rate Reduction and Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	1
Credit Card: | International card businesses:
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount		79	87
Credit Card: | International card businesses: | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	20
Credit Card: | International card businesses: | Interest rate reduction | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	20
Credit Card: | International card businesses: | Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	0
Credit Card: | International card businesses: | Interest Rate Reduction and Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	0
Consumer Banking:
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount		286	136
Consumer Banking: | Auto
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount		285	136
Consumer Banking: | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	250
Consumer Banking: | Entity Loan Modification Program | Auto
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	250
Consumer Banking: | Interest rate reduction | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	0
Consumer Banking: | Interest rate reduction | Entity Loan Modification Program | Auto
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	0
Consumer Banking: | Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	15
Consumer Banking: | Term Extension | Entity Loan Modification Program | Auto
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	15
Consumer Banking: | Interest Rate Reduction and Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	235
Consumer Banking: | Interest Rate Reduction and Term Extension | Entity Loan Modification Program | Auto
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	235
Commercial Banking:
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount		83	170
Commercial Banking: | Commercial and multifamily real estate
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount		27	50
Commercial Banking: | Commercial and industrial
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount		$ 56	$ 120
Commercial Banking: | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	97
Commercial Banking: | Entity Loan Modification Program | Commercial and multifamily real estate
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	46
Commercial Banking: | Entity Loan Modification Program | Commercial and industrial
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	51
Commercial Banking: | Interest rate reduction | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	0
Commercial Banking: | Interest rate reduction | Entity Loan Modification Program | Commercial and multifamily real estate
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	0
Commercial Banking: | Interest rate reduction | Entity Loan Modification Program | Commercial and industrial
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	0
Commercial Banking: | Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	97
Commercial Banking: | Term Extension | Entity Loan Modification Program | Commercial and multifamily real estate
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	46
Commercial Banking: | Term Extension | Entity Loan Modification Program | Commercial and industrial
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	51
Commercial Banking: | Interest Rate Reduction and Term Extension | Entity Loan Modification Program
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	0
Commercial Banking: | Interest Rate Reduction and Term Extension | Entity Loan Modification Program | Commercial and multifamily real estate
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	0
Commercial Banking: | Interest Rate Reduction and Term Extension | Entity Loan Modification Program | Commercial and industrial
Financing Receivable, Modified, Subsequent Default [Line Items]
Amount	$ 0