Investments (Net Realized Gains (Losses) And Losses Included In Net Realized Gains (Losses) And Other Comprehensive Income) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Investments, Debt and Equity Securities [Abstract]
OTTI on fixed maturities, gross	$ (13)	$ (9)	$ (26)	$ (15)
OTTI on fixed maturities recognized in OCI (pre-tax)	6	1	6	2
OTTI on fixed maturities, net	(7)	(8)	(20)	(13)
Fixed maturities, Gross realized gains excluding OTTI	28	54	72	90
Fixed maturities, Gross realized losses excluding OTTI	(16)	(26)	(51)	(46)
Total fixed maturities	5	20	1	31
OTTI on equity securities	(1)	(1)	(1)	(7)
Equity securities, Gross realized gains excluding OTTI	30	2	33	4
Equity securities, Gross realized losses excluding OTTI	0	0	(2)	(1)
Total equity securities	29	1	30	(4)
OTTI on other investments	0	(3)	0	(3)
Foreign exchange losses	(40)	(14)	(71)	(23)
Investment and embedded derivative instruments	27	(15)	28	(40)
Fair value adjustments on insurance derivative	104	2	59	(46)
S&P put options and futures	(2)	(72)	(14)	(91)
Other derivative instruments	(1)	9	(1)	7
Other	4	(1)	5	(8)
Total net realized gains (losses) (includes $34, $21, $31, and $27 reclassified from AOCI)	$ 126	$ (73)	$ 37	$ (177)