Service Fees and Other Revenue and Other Expenses - Service Fees and Other Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Non Interest Income [Line Items]
Total Service fees and other revenue	$ 11,939	$ 10,978	$ 35,186	$ 31,549
Service fees and other revenue
Non Interest Income [Line Items]
Service fees	375	353	1,114	1,072
Foreign currency-related revenue	374	338	1,071	867
Delinquency fees	245	211	717	583
Travel commissions and fees	183	155	476	374
Other fees and revenues	84	112	333	444
Total Service fees and other revenue	$ 1,261	$ 1,169	$ 3,711	$ 3,340