Derivative Financial Instruments - Gains and Losses on Derivative Instruments Held For Other Purpose (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ 1,055	$ 824	$ 2,082
Gain (loss) on instruments designated at fair value and related derivatives
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	1,040	824	2,131
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	(61)	229	364
Gain (loss) on instruments designated at fair value and related derivatives | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	0	(1)	(3)
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	1,139	592	1,809
Gain (loss) on instruments designated at fair value and related derivatives | Credit contracts
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	0	37	0
Other income (loss) | Interest rate contracts
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(2)	(6)	(1)
Other income (loss) | Credit contracts
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(19)	(18)	(24)
Other income (loss) | Other Contracts
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (2)	$ (9)	$ (63)