Deferred Policy Acquisition Costs (Deferred Policy Acquisition Costs And Asset Reconciliation Including The Amortized Deferred Policy Acquisition Costs) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deferred Policy Acquisition Costs [Abstract]
Deferred policy acquisition costs asset at January 1	$ 477	$ 458	$ 454
Capitalized deferred policy acquisition costs	734	661	627
Amortized deferred policy acquisition costs	(706)	(631)	(607)
Amortized shadow deferred policy acquisition costs	(35)	(11)	(16)
Deferred policy acquisition costs asset at December 31	$ 470	$ 477	$ 458