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, 2023	Dec. 31, 2022
Variable Interest Entities [Line Items]
Variable Interest Entity Nonconsolidated Carrying Amount Insurance Assets	$ 351	$ 490
Variable Interest Entity Nonconsolidated Carrying Amount Insurance Liabilities	836	840
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	20,861	21,639
Variable Interest Entity Nonconsolidated Carrying Amount Derivative Net Assets Or Liabilities	0
Fixed income securities, amortized cost	2,197	2,041
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	40	31
Variable Interest Entity [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Nonconsolidated Carrying Amount Derivative Net Assets Or Liabilities		1
Corporate Obligations [Member]
Variable Interest Entities [Line Items]
Fixed income securities, amortized cost	785	659
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	4	1
Municipal Bonds [Member]
Variable Interest Entities [Line Items]
Fixed income securities, amortized cost	72	44
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1	0
Municipal Bonds [Member] | Variable Interest Entity [Member]
Variable Interest Entities [Line Items]
Fixed income securities, amortized cost	88	99
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	$ 7	$ 1