v3.26.1
Accumulated Other Comprehensive Income - Activity in AOCI (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]    
Pretax unrealized losses $ (162) $ 974
Other comprehensive income (loss), tax effect 38 (233)
Other comprehensive (loss) income, net of tax (124) 741
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance 21,724 19,645
Net Activity (124) 741
Ending Balance 34,106 20,403
Accumulated Other Comprehensive Loss    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]    
Other comprehensive (loss) income, net of tax (124) 741
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance (3,110) (4,636)
Net Activity (124) 741
Ending Balance (3,234) (3,895)
Available-for-sale debt securities    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]    
Other comprehensive income (loss) before reclassifications, pre-tax activity (129) 633
Other comprehensive income (loss), before reclassifications, tax effect 29 (152)
Other comprehensive income (loss), before reclassifications, net activity 100 (481)
Pretax unrealized losses (129) 633
Other comprehensive income (loss), tax effect 29 (152)
Other comprehensive (loss) income, net of tax (100) 481
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance (2,231) (3,280)
Net Activity (100) 481
Ending Balance (2,331) (2,799)
Available-for-sale debt securities transferred to held-to-maturity securities    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]    
Reclassification adjustment, pre-tax activity 27 32
Reclassification adjustment, tax effect (5) (7)
Reclassification adjustment, net activity 22 25
Pretax unrealized losses 27 32
Other comprehensive income (loss), tax effect (5) (7)
Other comprehensive (loss) income, net of tax 22 25
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance (587) (684)
Net Activity 22 25
Ending Balance (565) (659)
Cash flow hedge derivatives    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]    
Other comprehensive income (loss) before reclassifications, pre-tax activity (81) 253
Other comprehensive income (loss), before reclassifications, tax effect 19 (60)
Other comprehensive income (loss), before reclassifications, net activity 62 (193)
Reclassification adjustment, pre-tax activity 21 56
Reclassification adjustment, tax effect (5) (14)
Reclassification adjustment, net activity 16 42
Pretax unrealized losses (60) 309
Other comprehensive income (loss), tax effect 14 (74)
Other comprehensive (loss) income, net of tax (46) 235
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance (275) (654)
Net Activity (46) 235
Ending Balance (321) (419)
Net periodic benefit costs    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]    
Pretax unrealized losses 0 0
Other comprehensive income (loss), tax effect 0 0
Other comprehensive (loss) income, net of tax 0 0
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance (15) (16)
Net Activity 0 0
Ending Balance (15) (16)
Other    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]    
Pretax unrealized losses 0 0
Other comprehensive income (loss), tax effect 0 0
Other comprehensive (loss) income, net of tax 0 0
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]    
Beginning Balance (2) (2)
Net Activity 0 0
Ending Balance $ (2) $ (2)