Line of Business Information - Components of Other (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Foreign exchange trading services	$ 1,614	$ 1,401	$ 1,265
Other fee revenue	236	289	180
Gains (losses) from sales of available-for-sale securities, net	4	(79)	(294)
Repositioning charges	(326)
Income before income tax expense	3,731	3,395	2,316
Net repositioning benefit	326	(2)	203
FDIC special assessment	60	99	387
Labor And Related Expense
Segment Reporting Information [Line Items]
Net repositioning benefit		(15)
Occupancy, Net
Segment Reporting Information [Line Items]
Net repositioning benefit		13
Other
Segment Reporting Information [Line Items]
Foreign exchange trading services	3	15	0
Client rescoping (revenue impact)	(24)	0	0
Other fee revenue	0	66	0
Gains (losses) from sales of available-for-sale securities, net	0	(81)	(294)
Deferred incentive compensation expense acceleration	0	(79)	0
Repositioning charges	(326)	2	(203)
Client rescoping (expense impact)	(18)	0	0
Other notable items	21	(111)	(427)
Income before income tax expense	(344)	(188)	(924)
Client rescoping (revenue impact) before taxes	(42)
Compensation and employee benefits expenses related to workforce rationalization	211
Occupancy costs related to real estate footprint optimization	69		21
Other changes	40	12	41
Net repositioning benefit			(182)
FDIC special assessment	(60)	99	$ 387
Other | Communications and Information Technology
Segment Reporting Information [Line Items]
Other changes	24
Other | Other Expense
Segment Reporting Information [Line Items]
Other changes	$ 22
Other | Labor And Related Expense
Segment Reporting Information [Line Items]
Net repositioning benefit		(15)
Other | Occupancy, Net
Segment Reporting Information [Line Items]
Net repositioning benefit		$ 13