Variable Interest Entities - Summary of Fair Value of Fixed Income Securities, by Asset-Type, Held by Consolidated Variable Interest Entities (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Variable Interest Entities [Line Items]
Variable Interest Entity Nonconsolidated Carrying Amount Insurance Assets	$ 2,195	$ 2,314
Variable Interest Entity Nonconsolidated Carrying Amount Insurance Liabilities	1,023	1,122
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	25,112	27,998
Variable Interest Entity Nonconsolidated Carrying Amount Derivative Net Assets Or Liabilities	5
Fixed income securities, amortized cost	2,140
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	141	149
Variable Interest Entity [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Nonconsolidated Carrying Amount Derivative Net Assets Or Liabilities		8
Municipal Bonds [Member] | Variable Interest Entity [Member]
Variable Interest Entities [Line Items]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	$ 29	$ 27