INVESTMENTS - Contractual and Economic Maturities of Investments in Fixed Maturities (Detail) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Available for sale:
Due in one year or less	$ 889
Due after one year through five years	8,483
Due after five years through 10 years	10,111
Due after 10 years	58,843
Mortgage- and asset-backed securities	380
Total fixed maturity securities, available for sale, amortized cost	78,706	$ 76,856
Held to maturity:
Due in one year or less	135
Due after one year through five years	1,112
Due after five years through 10 years	678
Due after 10 years	28,218
Mortgage- and asset-backed securities	20
Total fixed maturity securities, held to maturity, amortized cost	30,163	30,318
Available for sale:
Due in one year or less	950
Due after one year through five years	8,624
Due after five years through 10 years	11,034
Due after 10 years	66,902
Mortgage- and asset-backed securities	414
Total fixed maturity securities, available for sale, fair value	87,924	82,895
Held to maturity:
Due in one year or less	137
Due after one year through five years	1,187
Due after five years through 10 years	739
Due after 10 years	35,362
Mortgage- and asset-backed securities	21
Total fixed maturity securities, held to maturity, fair value	$ 37,446	$ 36,722