Derivative Financial Instruments - Collateral Held and Pledged (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Collateral held:
Cash (obligation to return cash collateral is recorded in short-term borrowings)	$ 152	$ 244
Securities at fair value - on-balance sheet securitization derivatives (not recorded in financial statements)		1
Total collateral held	152	245
Derivative asset at fair value including accrued interest	159	242
Collateral pledged to others:
Cash (right to receive return of cash collateral is recorded in investments)	95	147
Total collateral pledged	95	147
Derivative liability at fair value including accrued interest and premium receivable	$ 256	$ 271