Reinsurance (Earned Life Insurance Premiums On Ceded Business) (Details) (Life Insurance Segment [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Life Insurance Segment [Member]
Direct earned premiums	$ 235	$ 220	$ 211
Ceded earned premiums	(57)	(55)	(53)
Net earned premiums	$ 178	$ 165	$ 158