Guarantee Arrangements, Pledged Assets and Repurchase Agreements - Carrying Value and Contractual Amounts of our Sell Protection Credit Derivatives and Major Off-Balance Sheet Guarantee Arrangements (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Guarantor Obligations [Line Items]
Carrying Value	$ 104	$ 7
Notional / Maximum Exposure to Loss	14,683	10,474
Credit derivatives
Guarantor Obligations [Line Items]
Carrying Value	104	7
Notional / Maximum Exposure to Loss	6,319	2,174
Financial standby letters of credit, net of participations
Guarantor Obligations [Line Items]
Carrying Value	0	0
Notional / Maximum Exposure to Loss	5,462	5,339
Performance standby letters of credit, net of participations
Guarantor Obligations [Line Items]
Carrying Value	0	0
Notional / Maximum Exposure to Loss	2,902	2,961
Affiliated Entity | Credit derivatives
Guarantor Obligations [Line Items]
Notional / Maximum Exposure to Loss	2,314	1,591
Affiliated Entity | Financial and performance standby letters of credit
Guarantor Obligations [Line Items]
Notional / Maximum Exposure to Loss	$ 1,989	$ 1,969