Deferred Acquisition Costs - Deferred Policy Acquisition Costs and Asset Reconciliation (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs asset, beginning of period	$ 600	$ 571	$ 578	$ 565
Capitalized deferred policy acquisition costs	212	208	640	630
Amortized deferred policy acquisition costs	(207)	(195)	(620)	(598)
Amortized shadow deferred policy acquisition costs	4	6	11	(7)
Deferred policy acquisition costs asset, end of period	$ 609	$ 590	$ 609	$ 590