Investments (Net Realized Gains (Losses) And Losses Included In Net Realized Gains (Losses) And Other Comprehensive Income) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]
OTTI on fixed maturities, gross	$ (5)	$ (4)	$ (20)	$ (11)
OTTI on fixed maturities recognized in OCI (pre-tax)	1	0	3	0
OTTI on fixed maturities, net	(4)	(4)	(17)	(11)
Fixed maturities, Gross realized gains excluding OTTI	73	37	163	163
Fixed maturities, Gross realized losses excluding OTTI	(51)	(16)	(97)	(68)
Total fixed maturities	18	17	49	84
OTTI on equity securities	0	0	(7)	(1)
Equity securities, Gross realized gains excluding OTTI	4	8	8	18
Equity securities, Gross realized losses excluding OTTI	(60)	(1)	(61)	(4)
Total equity securities	(56)	7	(60)	13
OTTI on other investments	0	0	(3)	(2)
Foreign exchange gains (losses)	(19)	(26)	(42)	45
Investment and embedded derivative instruments	(13)	4	(53)	62
Fair value adjustments on insurance derivative	(80)	134	(126)	563
S&P put options and futures	(15)	(95)	(106)	(413)
Other derivative instruments	45	(1)	52	(2)
Other	0	0	(8)	0
Total net realized gains (losses)	$ (120)	$ 40	$ (297)	$ 350