Investments (Roll-Forward Of Pre-Tax Credit Losses Related To Fixed Maturities For Which Portion Of Other-Than-Temporary Impairment Was Recognized In 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
Roll-Forward Of Pre-Tax Credit Losses Related To Fixed Maturities For Which Portion Of Other-Than-Temporary Impairment Was Recognized In Other Comprehensive Income [Roll Forward]
Balance of credit losses related to securities still held – beginning of period	$ 35	$ 35	$ 37	$ 43
Additions where no OTTI was previously recorded	5	4	7	4
Additions where an OTTI was previously recorded	1	2	3	3
Reductions for securities sold during the period	(17)	(1)	(23)	(10)
Balance of credit losses related to securities still held – end of period	$ 24	$ 40	$ 24	$ 40