Investments (Schedule Of Fixed Maturities By Contractual Maturity) (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]
Available for sale, Due in 1 year or less, Amortized Cost	$ 2,513	$ 2,387
Available for sale, Due after 1 year through 5 years, Amortized Cost	15,095	14,139
Available for sale, Due after 5 years though 10 years, Amortized Cost	15,917	16,200
Available for sale, Due after 10 years, Amortized Cost	5,009	4,743
Available for sale, Subtotal, Amortized Cost	38,534	37,469
Available for sale, Mortgage-backed securities, Amortized Cost	11,185	10,937
Available for sale, Amortized Cost	49,719	48,406
Available for sale, Fair Value	51,601	49,254
Held to maturity, Due in 1 year or less, Amortized Cost	483	401
Held to maturity, Due after 1 year through 5 years, Amortized Cost	2,590	2,284
Held to maturity, Due after 5 years through 10 years, Amortized Cost	1,157	1,686
Held to maturity, Due after 10 years, Amortized Cost	357	386
Held to maturity, Subtotal, Amortized Cost	4,587	4,757
Held to maturity, Mortgage backed securities, Amortized Cost	1,187	1,341
Available for sale, Due in 1 year or less, Fair Value	2,537	2,411
Available for sale, Due after 1 year through 5 years, Fair Value	15,692	14,602
Available for sale, Due after 5 years through 10 years, Fair Value	16,575	16,535
Available for sale, Due after 10 years, Fair Value	5,379	4,812
Available for sale, Subtotal, Fair Value	40,183	38,360
Available for sale, Mortgage backed securities, Fair Value	11,418	10,894
Held to maturity, Due in 1 year or less, Fair Value	489	405
Held to maturity, Due after 1 year through 5, Fair Value	2,693	2,363
Held to maturity, Due after 5 years through 10 years, Fair Value	1,206	1,723
Held to maturity, Due after 10 years, Fair Value	386	393
Held to maturity, Subtotal, Fair Value	4,774	4,884
Held to maturity, Mortgage backed securities, Fair Value	1,241	1,379
Held-to-maturity Securities	5,774	6,098
Held to maturity, Fair Value	$ 6,015	$ 6,263