Investments (Distribution By Contractual Maturity Of Available-For-Sale and Held-To-Maturity Investments) (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Available For Sale Securities [Abstract]
Total Available-For-Sale, Amortized Cost	$ 6,783	$ 6,824
Total available-for-sale, fair value	6,860	6,692
Held To Maturity Securities [Abstract]
Total Held-To-Maturity, Amortized Cost	2,787	2,801
Total held-to- maturity, fair value	2,780	2,651
Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Due in one year or less	875
Due after one year through five years	1,387
Due after five years through ten years	1,000
Due after ten years	1,524
Mortgage-Backed and Asset-Backed	1,601
Total Available-For-Sale, Amortized Cost	6,387	5,897
Due in one year or less	875
Due after one year through five years	1,410
Due after five years through ten years	1,019
Due after ten years	1,582
Mortgage-Backed and Asset-Backed	1,577
Total available-for-sale, fair value	6,463	5,764
Fixed Maturities [Member] | Variable Interest Entity Primary Beneficiary [Member]
Held To Maturity Securities [Abstract]
Due in one year or less	0
Due after one year through five years	0
Due after five years through ten years	0
Due after ten years	2,787
Mortgage-Backed and Asset-Backed	0
Total Held-To-Maturity, Amortized Cost	2,787
Due in one year or less	0
Due after one year through five years	0
Due after five years through ten years	0
Due after ten years	2,780
Mortgage-Backed and Asset-Backed	0
Total held-to- maturity, fair value	$ 2,780