Fair Value Measurements - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Unfunded commitments, equity securities measured at net asset value	$ 27			$ 27		$ 29
Revaluation period				90 days
Deferred fees	3			$ 3		4
Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Transfers Out of Level 3	116	$ 27		205	$ 115
Fair Value Liability, Transfers Into Level 3	161	9		528	154
Assets Transfers out of Level 3	9	0		52	(52)
Level 3 | Equity contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivatives, net, Transfers out of Level 3	9	0	$ 27	52	(28)
Derivatives, net, Transfers into Level 3	(17)	38		5	(30)
Level 3 | Asset-backed securities available-for-sale
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets Transfers out of Level 3	0	0		0	0
Unfunded Loan Commitment
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Deferred fees	150			150		$ 151
Domestic deposits | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Transfers Out of Level 3	27	9		30	90
Fair Value Liability, Transfers Into Level 3	26	0		156	109
Long-term debt | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Transfers Out of Level 3	89	18		175	25
Fair Value Liability, Transfers Into Level 3	$ 135	$ 9		$ 372	45
Residential mortgage asset-backed securities | Level 3 | Trading assets, excluding derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets Transfers out of Level 3			$ 24		$ (24)