Service Fees and Other Revenue and Other Expenses - Other Expenses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Service Fees and Other Revenue and Other Expenses [Abstract]
Data processing and equipment	$ 657	$ 660
Professional services	455	440
Other	364	462
Total Other expenses	$ 1,476	$ 1,562