Investments (Schedule Of Fixed Maturities By Contractual Maturity) (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Available for sale, Due in 1 year or less, Fair Value & Net Carrying Value	$ 4,393	$ 4,498
Available for sale, Due after 1 year through 5 years, Fair Value & Net Carrying Value	25,136	25,542
Available for sale, Due after 5 years through 10 years, Fair Value & Net Carrying Value	27,033	28,207
Available for sale, Due after 10 years, Fair Value & Net Carrying Value	13,112	14,372
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value	69,674	72,619
Available for sale, Mortgage backed securities, Fair Value & Net Carrying Value	19,805	20,489
Available for sale, Fair Value	89,479	93,108
Debt securities, Held-to-maturity, maturity, allocated and single maturity date, within one year, net carrying value	871	888
Held to maturity, Due in 1 year or less, Fair Value	872	894
Held-to-maturity, after one through five years, net carrying value	3,754	3,744
Held to maturity, Due after 1 year through 5, Fair Value	3,742	3,846
Held-to-maturity, after 5 through 10 years, net carrying value	2,004	2,242
Held to maturity, Due after 5 years through 10 years, Fair Value	2,015	2,349
Held-to-maturity, after 10 years, net carrying value	1,500	1,514
Held to maturity, Due after 10 years, Fair Value	1,575	1,755
Debt securities, Held-to-maturity, maturity, allocated and single maturity date, net carrying value	8,129	8,388
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Fair Value	8,204	8,844
Held-to-maturity, MBS, net carrying value	1,689	1,730
Held to maturity, Mortgage backed securities, Fair Value	1,684	1,803
Debt securities, held to maturity, net carrying value	9,818	10,118
Held to maturity, Fair Value	$ 9,888	$ 10,647