Investments (Schedule Of Fixed Maturities By Contractual Maturity) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Investments, Debt and Equity Securities [Abstract]
Available for sale, Due in 1 year or less, Amortized Cost	$ 2,387	$ 1,887
Available for sale, Due after 1 year through 5 years, Amortized Cost	14,139	13,411
Available for sale, Due after 5 years though 10 years, Amortized Cost	16,200	15,032
Available for sale, Due after 10 years, Amortized Cost	4,743	4,285
Available for sale, Subtotal, Amortized Cost	37,469	34,615
Available for sale, Mortgage-backed securities, Amortized Cost	10,937	10,051
Available for sale, Amortized Cost	48,406	44,666
Available for sale, Due in 1 year or less, Fair Value	2,411	1,906
Available for sale, Due after 1 year through 5 years, Fair Value	14,602	14,010
Available for sale, Due after 5 years through 10 years, Fair Value	16,535	16,153
Available for sale, Due after 10 years, Fair Value	4,812	4,764
Available for sale, Subtotal, Fair Value	38,360	36,833
Available for sale, Mortgage backed securities, Fair Value	10,894	10,473
Available for sale, Fair Value	49,254	47,306
Held to maturity, Due in 1 year or less, Amortized Cost	401	656
Held to maturity, Due after 1 year through 5 years, Amortized Cost	2,284	1,870
Held to maturity, Due after 5 years through 10 years, Amortized Cost	1,686	2,119
Held to maturity, Due after 10 years, Amortized Cost	386	597
Held to maturity, Subtotal, Amortized Cost	4,757	5,242
Held to maturity, Mortgage backed securities, Amortized Cost	1,341	2,028
Held-to-maturity Securities	6,098	7,270
Held to maturity, Due in 1 year or less, Fair Value	405	659
Held to maturity, Due after 1 year through 5, Fair Value	2,363	1,950
Held to maturity, Due after 5 years through 10 years, Fair Value	1,723	2,267
Held to maturity, Due after 10 years, Fair Value	393	641
Held to maturity, Subtotal, Fair Value	4,884	5,517
Held to maturity, Mortgage backed securities, Fair Value	1,379	2,116
Held to maturity, Fair Value	$ 6,263	$ 7,633