Investments - Fair Values and Unrealized Losses by Investment Category and by Duration of Securities' Continuous Unrealized Loss Position (Detail) - Fixed maturities - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Investments, Unrealized Loss Position
Less than 12 months Fair Value	$ 7,483	$ 1,047
Less than 12 Months, Unrealized Loss	630	15
12 months or more, Fair Value	151	28
12 months or longer, Unrealized Loss	32	1
Total Fair Value	7,634	1,075
Gross unrealized loss	662	16
Corporate
Investments, Unrealized Loss Position
Less than 12 months Fair Value	4,768	861
Less than 12 Months, Unrealized Loss	398	13
12 months or more, Fair Value	107	15
12 months or longer, Unrealized Loss	26	0
Total Fair Value	4,875	876
Gross unrealized loss	424	13
States, municipalities and political subdivisions
Investments, Unrealized Loss Position
Less than 12 months Fair Value	2,341	105
Less than 12 Months, Unrealized Loss	223	2
12 months or more, Fair Value	20	2
12 months or longer, Unrealized Loss	6	1
Total Fair Value	2,361	107
Gross unrealized loss	229	3
Commercial mortgage-backed
Investments, Unrealized Loss Position
Less than 12 months Fair Value	237	10
Less than 12 Months, Unrealized Loss	7	0
12 months or more, Fair Value	10	11
12 months or longer, Unrealized Loss	0	0
Total Fair Value	247	21
Gross unrealized loss	7	0
United States government
Investments, Unrealized Loss Position
Less than 12 months Fair Value	85	48
Less than 12 Months, Unrealized Loss	2	0
12 months or more, Fair Value	11	0
12 months or longer, Unrealized Loss	0	0
Total Fair Value	96	48
Gross unrealized loss	2	0
Government-sponsored enterprises
Investments, Unrealized Loss Position
Less than 12 months Fair Value	36	7
Less than 12 Months, Unrealized Loss	0	0
12 months or more, Fair Value	3	0
12 months or longer, Unrealized Loss	0	0
Total Fair Value	39	7
Gross unrealized loss	0	0
Foreign government
Investments, Unrealized Loss Position
Less than 12 months Fair Value	16	16
Less than 12 Months, Unrealized Loss	0	0
12 months or more, Fair Value	0	0
12 months or longer, Unrealized Loss	0	0
Total Fair Value	16	16
Gross unrealized loss	$ 0	$ 0