Investments (Distribution By Contractual Maturity Of Available-For-Sale and Held-To-Maturity Investments) (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Held To Maturity Securities [Abstract]
Total Held-To-Maturity, amortized cost	$ 2,772	$ 2,801
Total Held-To-Maturity, fair value	2,730	2,651
Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Due in one year or less	634
Due after one year through five years	1,509
Due after five years through ten years	963
Due after ten years	1,483
Mortgage-Backed and Asset-Backed	1,544
Total Available-For-Sale, amortized cost	6,133
Due in one year or less	635
Due after one year through five years	1,528
Due after five years through ten years	979
Due after ten years	1,478
Mortgage-Backed and Asset-Backed	1,512
Total Available-For-Sale, fair value	6,132
Fixed Maturities [Member] \| Variable Interest Entity Primary Beneficiary [Member]
Held To Maturity Securities [Abstract]
Due after ten years	2,772
Total Held-To-Maturity, amortized cost	2,772
Due after ten years	2,730
Total Held-To-Maturity, fair value	$ 2,730

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Amount of available-for-sale debt securities at cost, net of adjustments, which include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.