v3.26.3
AOCI (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
AOCI, Net of Tax [Roll Forward]        
Beginning balance     $ 65,189  
Amounts reclassified from AOCI:        
Total OCI, net of tax $ (1,556) $ 520 (2,503) $ 1,840
Ending balance 61,472   61,472  
Total        
AOCI, Net of Tax [Roll Forward]        
Beginning balance (6,716) (6,893) (5,769) (8,213)
OCI before reclassifications, net of tax (2,769) 447 (3,863) 1,634
Amounts reclassified from AOCI:        
Total OCI, net of tax (1,556) 520 (2,503) 1,840
Ending balance (8,272) (6,373) (8,272) (6,373)
Total | Amounts reclassified from AOCI        
Amounts reclassified from AOCI:        
Before tax 1,592 93 1,785 264
Tax effect 379 20 425 58
Amounts reclassified, net of tax 1,213 73 1,360 206
Pension and OPEB Costs        
AOCI, Net of Tax [Roll Forward]        
Beginning balance (386) (641) (381) (648)
OCI before reclassifications, net of tax (21) (46) (28) (40)
Amounts reclassified from AOCI:        
Total OCI, net of tax (19) (46) (24) (39)
Ending balance (405) (687) (405) (687)
Pension and OPEB Costs | Amounts reclassified from AOCI        
Amounts reclassified from AOCI:        
Before tax 2 0 5 1
Tax effect 0 0 1 0
Amounts reclassified, net of tax 2 0 4 1
Cash Flow Hedges        
AOCI, Net of Tax [Roll Forward]        
Beginning balance (1,035) (157) (173) (861)
OCI before reclassifications, net of tax (923) (48) (1,855) 515
Amounts reclassified from AOCI:        
Total OCI, net of tax (857) 30 (1,719) 734
Ending balance (1,892) (127) (1,892) (127)
Cash Flow Hedges | Amounts reclassified from AOCI        
Amounts reclassified from AOCI:        
Before tax 87 101 178 286
Tax effect 21 23 42 67
Amounts reclassified, net of tax 66 78 136 219
AFS Securities        
AOCI, Net of Tax [Roll Forward]        
Beginning balance (3,486) (4,079) (3,306) (4,573)
OCI before reclassifications, net of tax (1,827) 541 (1,985) 1,153
Amounts reclassified from AOCI:        
Total OCI, net of tax (735) 480 (915) 974
Ending balance (4,221) (3,599) (4,221) (3,599)
AFS Securities | Amounts reclassified from AOCI        
Amounts reclassified from AOCI:        
Before tax 1,434 (81) 1,405 (232)
Tax effect 342 (20) 335 (53)
Amounts reclassified, net of tax 1,092 (61) 1,070 (179)
HTM Securities        
AOCI, Net of Tax [Roll Forward]        
Beginning balance (1,812) (2,016) (1,909) (2,125)
OCI before reclassifications, net of tax 0 0 0 0
Amounts reclassified from AOCI:        
Total OCI, net of tax 53 56 150 165
Ending balance (1,759) (1,960) (1,759) (1,960)
HTM Securities | Amounts reclassified from AOCI        
Amounts reclassified from AOCI:        
Before tax 69 73 197 209
Tax effect 16 17 47 44
Amounts reclassified, net of tax 53 56 150 165
Other, net        
AOCI, Net of Tax [Roll Forward]        
Beginning balance 3 0 0 (6)
OCI before reclassifications, net of tax 2 0 5 6
Amounts reclassified from AOCI:        
Total OCI, net of tax 2 0 5 6
Ending balance 5 0 5 0
Other, net | Amounts reclassified from AOCI        
Amounts reclassified from AOCI:        
Before tax 0 0 0 0
Tax effect 0 0 0 0
Amounts reclassified, net of tax $ 0 $ 0 $ 0 $ 0