Scheduled Maturity Distribution of Fixed Maturity Securities (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Amortized cost or cost
Due one year or less	$ 1,476
Due after one year through five years	9,646
Due after five years through ten years	13,164
Due after ten years	23,112
Subtotal	47,398
Amortized cost or cost, fixed maturity securities	55,252
Fair value
Due one year or less	1,499
Due after one year through five years	10,265
Due after five years through ten years	14,863
Due after ten years	29,452
Subtotal	56,079
Fair value, fixed maturity securities	64,416	$ 60,339
Residential mortgage-backed
Amortized cost or cost
Fixed maturity securities	1,825
Fair value
Fixed maturity securities	2,075
Commercial mortgage-backed
Amortized cost or cost
Fixed maturity securities	2,775
Fair value
Fixed maturity securities	2,976
Other asset-backed
Amortized cost or cost
Fixed maturity securities	3,254
Fair value
Fixed maturity securities	$ 3,286