v3.25.3
Shareholders' Equity - Adjustments to Accumulated Other Comprehensive Income (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Jun. 30, 2025
Mar. 31, 2025
Sep. 30, 2024
Jun. 30, 2024
Mar. 31, 2024
Sep. 30, 2025
Sep. 30, 2024
Class of Stock [Line Items]                
Gains (losses) from sales of available-for-sale securities, net $ (1)     $ 80     $ (1) $ 80
Net interest income (715)     (723)     (2,158) (2,174)
Compensation and employee benefits expenses (1,162)     (1,134)     (3,704) (3,485)
Net income (861) $ (693) $ (644) (730) $ (711) $ (463) (2,198) (1,904)
Income tax expense 241     195     615 531
Amounts Reclassified into Earnings                
Class of Stock [Line Items]                
Net income 52     139     168 303
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 (1)     59     (1) 59
Net interest income 27     42     87 312
Net realized gains from sales of available-for-sale securities, tax             0 21
Amortization of net unrealized gain (loss), before adjustment, tax 9     15     39 113
Amounts Reclassified into Earnings | Net Unrealized Gains (Losses) on Cash Flow Hedges                
Class of Stock [Line Items]                
Net interest income 26     38     82 (69)
Net realized gains from sales of available-for-sale securities, tax $ 8     $ 13     25 (25)
Amounts Reclassified into Earnings | Amortization of Actuarial Losses                
Class of Stock [Line Items]                
Compensation and employee benefits expenses             0 1
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, Tax             $ 0 $ 0