v3.25.2
Comprehensive income - Components of Other Comprehensive Income (Loss) and Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) to Net Income (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance $ 28,991 $ 27,169 $ 29,027 $ 26,957
Other comprehensive income (loss), net of Tax, Portion attributable to parent 125 38 379 (92)
Ending balance 28,525 28,424 28,525 28,424
AOCI Attributable to Parent        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Equity, attributable to parent, beginning balance     (219) (616)
Beginning balance     55 157
Beginning balance 90 (589) (164) (459)
Other comprehensive income (loss) before reclassifications:     426 (316)
Other comprehensive income (loss) before reclassifications, tax     (108) 78
OCI, before reclassifications, net of tax, attributable to parent     318 (238)
Total other comprehensive income (loss)     508 (120)
Deferred income taxes and credits     (129) 28
Other comprehensive income (loss), net of Tax, Portion attributable to parent     379 (92)
Equity, attributable to parent, ending balance 289 (736) 289 (736)
Ending balance (74) 185 (74) 185
Ending balance 215 (551) 215 (551)
Investment Securities        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Equity, attributable to parent, beginning balance     (205) (251)
Beginning balance     (153)  
Other comprehensive income (loss) before reclassifications:     287 (1)
Other comprehensive income (loss) before reclassifications, tax     (73) 0
OCI, before reclassifications, net of tax, attributable to parent     214 (1)
Amounts reclassified from accumulated other comprehensive income (loss) that (increase) decrease net income:       13
Reclassification from AOCI, current period, tax       (4)
Reclassification from AOCI, current period, net of tax, attributable to parent       9
Total other comprehensive income (loss)     287 12
Other comprehensive income (loss), net of Tax, Portion attributable to parent     214  
Equity, attributable to parent, ending balance 82 (239) 82 (239)
Ending balance 61   61  
Cash Flow Hedges        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Equity, attributable to parent, beginning balance     (135) (203)
Beginning balance     (101)  
Other comprehensive income (loss) before reclassifications:     134 (313)
Other comprehensive income (loss) before reclassifications, tax     (34) 78
OCI, before reclassifications, net of tax, attributable to parent     100 (235)
Amounts reclassified from accumulated other comprehensive income (loss) that (increase) decrease net income:     86 186
Reclassification from AOCI, current period, tax     (22) (46)
Reclassification from AOCI, current period, net of tax, attributable to parent     64 140
Total other comprehensive income (loss)     220 (127)
Other comprehensive income (loss), net of Tax, Portion attributable to parent     164  
Equity, attributable to parent, ending balance 85 (330) 85 (330)
Ending balance 63   63  
Defined Benefit Plans        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Equity, attributable to parent, beginning balance     131 (155)
Beginning balance     98  
Other comprehensive income (loss) before reclassifications:     0 0
Total other comprehensive income (loss)     (4) (3)
Other comprehensive income (loss), net of Tax, Portion attributable to parent     (3)  
Equity, attributable to parent, ending balance 127 (158) 127 (158)
Ending balance 95   95  
Prior Service Credit        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Amounts reclassified from accumulated other comprehensive income (loss) that (increase) decrease net income:     (1) (1)
Reclassification from AOCI, current period, tax     0 0
Reclassification from AOCI, current period, net of tax, attributable to parent     (1) (1)
Actuarial Gains        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Amounts reclassified from accumulated other comprehensive income (loss) that (increase) decrease net income:     (3) (2)
Reclassification from AOCI, current period, tax     1 0
Reclassification from AOCI, current period, net of tax, attributable to parent     (2) (2)
Other        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Equity, attributable to parent, beginning balance     (10) (7)
Beginning balance     (8)  
Other comprehensive income (loss) before reclassifications:     5 (2)
Other comprehensive income (loss) before reclassifications, tax     (1) 0
OCI, before reclassifications, net of tax, attributable to parent     4 (2)
Total other comprehensive income (loss)     5 (2)
Other comprehensive income (loss), net of Tax, Portion attributable to parent     4  
Equity, attributable to parent, ending balance (5) $ (9) (5) $ (9)
Ending balance $ (4)   $ (4)