Service Fees and Other Revenue and Other Expenses - Other Expenses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Service Fees and Other Revenue and Other Expenses [Abstract]
Data processing and equipment	$ 720	$ 701	$ 1,425	$ 1,358
Professional services	591	542	1,132	997
Gain on sale of Accertify	0	(531)	0	(531)
Other	375	326	775	690
Total Other expenses	$ 1,686	$ 1,038	$ 3,332	$ 2,514