v3.26.1
Shareholders' Equity - Accumulated Other Comprehensive Income/(Loss), Net of Tax (Detail) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance $ 124,972  
Other comprehensive income/(loss) adjustments, net of tax 348 $ 633
Ending balance 122,782 124,300
Currency translation    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance (804) (815)
Other comprehensive income/(loss) adjustments, net of tax (27) (35)
Ending balance (831) (850)
Debt valuation adjustment    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance (1,062) (386)
Other comprehensive income/(loss) adjustments, net of tax 1,148 232
Ending balance 86 (154)
Pension and postretirement liabilities    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance (496) (528)
Other comprehensive income/(loss) adjustments, net of tax 1 10
Ending balance (495) (518)
Available-for-sale securities    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance 103 (972)
Other comprehensive income/(loss) adjustments, net of tax (753) 420
Ending balance (650) (552)
Cash flow hedges    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance (1) (1)
Other comprehensive income/(loss) adjustments, net of tax (21) 6
Ending balance (22) 5
Accumulated other comprehensive income/(loss)    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance (2,260) (2,702)
Other comprehensive income/(loss) adjustments, net of tax 348 633
Ending balance $ (1,912) $ (2,069)