Shareholders' Equity - Adjustments to Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Class of Stock [Line Items]
Gains (losses) from sales of available-for-sale securities, net	$ 4	$ (79)	$ (294)
Net interest income	(2,960)	(2,923)	(2,759)
Compensation and employee benefits expenses	5,035	4,697	4,744
Net income	2,945	2,687	1,944
Amounts Reclassified into Earnings
Class of Stock [Line Items]
Net income	210	414	582
Amounts Reclassified into Earnings | Net Unrealized Gains (Losses) on Investment Securities
Class of Stock [Line Items]
Gains (losses) from sales of available-for-sale securities, net	(2)	59	213
Net interest income	107	393	215
Gains (losses) from sales of available-for-sale securities, net tax	(2)	21	81
Net interest income tax	47	137	81
Amounts Reclassified into Earnings | Net Unrealized Gains (Losses) on Cash Flow Hedges
Class of Stock [Line Items]
Net interest income	104	(40)	153
Net realized gains from sales of available-for-sale securities tax	31	(14)	55
Amounts Reclassified into Earnings | Amortization of Actuarial Losses
Class of Stock [Line Items]
Compensation and employee benefits expenses	1	2	1
Amortization of actuarial losses tax	$ 0	$ 0	$ 0