Financial Instruments - Gross Notional Amounts of Outstanding Derivative Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Foreign exchange derivatives \| Derivatives designated as hedging instruments: \| Cash flow hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	$ 25,141	$ 23,852
Foreign exchange derivatives \| Derivatives designated as hedging instruments: \| Net investment hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	6,987	14,203
Foreign exchange derivatives \| Derivatives not designated as hedging instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	54,084	56,085
Interest rate derivatives \| Derivatives designated as hedging instruments: \| Fair value hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	7,000	0
Equity derivatives \| Derivatives not designated as hedging instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	21,091	0
Credit derivatives \| Derivatives not designated as hedging instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	48,012	16,940
Other derivatives \| Derivatives not designated as hedging instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	$ 11,420	$ 15,900