Business Segments - Summary of Accounting Change Impact (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 1,705	$ 2,069	$ 2,083
Other income	$ (141)	(154)	(13)
Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		2,060	1,904
Other income		1,610	1,430
MSS | Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		41	31
Other income		418	334
CC | Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		(178)	10
Other income		182	(13)
As Previously Reported | Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		2,060	1,904
Other income		1,610	1,430
As Previously Reported | MSS | Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		(108)	47
Other income		567	318
As Previously Reported | CC | Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		(29)	(6)
Other income		$ 33	$ 3