Service Fees and Other Revenue and Other Expenses - Other Expenses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Service Fees and Other Revenue and Other Expenses [Abstract]
Data processing and equipment	$ 725	$ 704	$ 2,083	$ 2,041
Professional services	579	477	1,576	1,384
Gain on sale of Accertify	0	0	(531)	0
Other	476	424	1,166	1,288
Total Other expenses	$ 1,780	$ 1,605	$ 4,294	$ 4,713