Deferred Policy Acquisition Costs and Asset Reconciliation, Including the Amortized Deferred Policy Acquisition Costs (Detail) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Deferred policy acquisition costs asset, beginning of period	$ 511	$ 485	$ 488	$ 481
Capitalized deferred policy acquisition costs	182	168	543	510
Amortized deferred policy acquisition costs	(177)	(167)	(510)	(492)
Amortized shadow deferred policy acquisition costs	(4)	(17)	(9)	(30)
Deferred policy acquisition costs asset, end of period	$ 512	$ 469	$ 512	$ 469