v3.26.1
Accumulated Other Comprehensive Loss (Details) - USD ($)
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]        
Balance at beginning of period     $ 12,439,000,000  
Total other comprehensive income (loss) $ 26,000,000 $ (24,000,000) (39,000,000) $ 89,000,000
Balance at end of period 12,757,000,000 12,010,000,000 12,757,000,000 12,010,000,000
Accumulated other comprehensive loss        
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]        
Balance at beginning of period (1,444,000,000) (1,659,000,000) (1,379,000,000) (1,772,000,000)
Total other comprehensive income (loss) 26,000,000 (24,000,000) (39,000,000) 89,000,000
Balance at end of period (1,418,000,000) (1,683,000,000) (1,418,000,000) (1,683,000,000)
Unrealized gains (losses) on investment securities        
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]        
Balance at beginning of period (1,343,000,000) (1,543,000,000) (1,238,000,000) (1,732,000,000)
Net unrealized gains (losses) arising during the period, net of tax 36,000,000 25,000,000 (62,000,000) 215,000,000
Reclassification adjustment for (gains) losses realized in net income (loss), net of tax (7,000,000) (5,000,000) (15,000,000) (7,000,000)
Amortization of net unrealized (gains) losses on securities transferred from available-for-sale to held-to-maturity realized in net income, net of tax     1,000,000 1,000,000
Total other comprehensive income (loss) 29,000,000 20,000,000 (76,000,000) 209,000,000
Balance at end of period (1,314,000,000) (1,523,000,000) (1,314,000,000) (1,523,000,000)
Tax on net unrealized gains (losses) arising during period (less than) 11,000,000 8,000,000 (19,000,000) 72,000,000
Tax on reclassification adjustment (less than) (2,000,000) (1,000,000) (5,000,000) (2,000,000)
Tax on amortization of net unrealized losses on securities transferred from available-for-sale to held-to-maturity realized in net income (loss) (less than)     1,000,000 1,000,000
Unrealized gains (losses) on fair value option liabilities attributable to our own credit spread        
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]        
Balance at beginning of period 12,000,000 9,000,000 (28,000,000) 6,000,000
Net unrealized gains (losses) arising during the period, net of tax (27,000,000) (7,000,000) 13,000,000 (4,000,000)
Total other comprehensive income (loss) (27,000,000) (7,000,000) 13,000,000 (4,000,000)
Balance at end of period (15,000,000) 2,000,000 (15,000,000) 2,000,000
Tax on net unrealized gains (losses) arising during period (less than) (9,000,000) (2,000,000) 4,000,000 (1,000,000)
Unrealized gains (losses) on derivatives designated as cash flow hedges        
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]        
Balance at beginning of period (116,000,000) (131,000,000) (116,000,000) (52,000,000)
Net unrealized gains (losses) arising during the period, net of tax 14,000,000 (49,000,000) 2,000,000 (136,000,000)
Reclassification adjustment for (gains) losses realized in net income (loss), net of tax 11,000,000 12,000,000 23,000,000 20,000,000
Total other comprehensive income (loss) 25,000,000 (37,000,000) 25,000,000 (116,000,000)
Balance at end of period (91,000,000) (168,000,000) (91,000,000) (168,000,000)
Tax on net unrealized gains (losses) arising during period (less than) 5,000,000 (17,000,000) 1,000,000 (45,000,000)
Tax on reclassification adjustment (less than) 4,000,000 5,000,000 8,000,000 7,000,000
Pension and postretirement benefit liability        
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]        
Balance at beginning of period 3,000,000 6,000,000 3,000,000 6,000,000
Net unrealized gains (losses) arising during the period, net of tax (1,000,000) 0 (1,000,000) 0
Total other comprehensive income (loss) (1,000,000) 0 (1,000,000) 0
Balance at end of period 2,000,000 6,000,000 2,000,000 6,000,000
Tax on net unrealized gains (losses) arising during period (less than) $ (1,000,000) $ 0 $ (1,000,000) $ 0