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		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Investments, Debt and Equity Securities [Abstract]
OTTI on fixed maturities, gross	$ (9)	$ (6)	$ (15)	$ (7)
OTTI on fixed maturities recognized in OCI (pre-tax)	1	0	2	0
OTTI on fixed maturities, net	(8)	(6)	(13)	(7)
Fixed maturities, Gross realized gains excluding OTTI	54	64	90	126
Fixed maturities, Gross realized losses excluding OTTI	(26)	(27)	(46)	(52)
Total fixed maturities	20	31	31	67
OTTI on equity securities	(1)	0	(7)	(1)
Equity securities, Gross realized gains excluding OTTI	2	8	4	10
Equity securities, Gross realized losses excluding OTTI	0	(1)	(1)	(3)
Total equity securities	1	7	(4)	6
OTTI on other investments	(3)	(1)	(3)	(2)
Foreign exchange gains (losses)	(14)	(5)	(23)	71
Investment and embedded derivative instruments	(15)	40	(40)	58
Fair value adjustments on insurance derivative	2	101	(46)	429
S&P put options and futures	(72)	(68)	(91)	(318)
Other derivative instruments	9	(1)	7	(1)
Other	(1)	0	(8)	0
Total net realized gains (losses)	$ (73)	$ 104	$ (177)	$ 310