Derivative Financial Instruments - Gains and Losses on Derivative Instruments Held For Other Purpose (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ 70	$ 438
Gain (loss) on instruments designated at fair value and related derivatives
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	98	454
Gain (loss) on instruments designated at fair value and related derivatives | Interest rate contracts
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(54)	43
Gain (loss) on instruments designated at fair value and related derivatives | Equity contracts
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	151	412
Other income (loss) | Credit contracts
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(25)	(15)
Other income (loss) | Other Contracts
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (2)	$ (2)