Service Fees and Other Revenue and Other Expenses - Other Expenses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Service Fees and Other Revenue and Other Expenses [Abstract]
Data processing and equipment	$ 701	$ 677	$ 1,358	$ 1,337
Professional services	542	467	997	907
Gain on sale of Accertify	(531)	0	(531)	0
Other	326	402	690	864
Total Other expenses	$ 1,038	$ 1,546	$ 2,514	$ 3,108