Business Segments - Summary of Accounting Change Impact (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 426	$ 483
Other income	$ (34)	(17)
Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		543
Other income		386
MSS | Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		13
Other income		96
CC | Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		(107)
Other income		91
As Previously Reported | Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		543
Other income		386
As Previously Reported | MSS | Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		(68)
Other income		177
As Previously Reported | CC | Operating Segments
Segment Reporting Information [Line Items]
Net interest income (expense)		(26)
Other income		$ 10