Reinsurance (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Ceded Premiums And Fees [Abstract]
Individual life insurance and annuity business sold	$ 51,000,000	$ 47,000,000
Other	66,000,000	58,000,000
Total	117,000,000	105,000,000
Reinsurance Recoveries [Abstract]
Individual life insurance and annuity business sold	68,000,000	65,000,000
Other	54,000,000	47,000,000
Total	122,000,000	112,000,000
Reinsurance Text Details [Abstract]
Reinsurance Recoverable Retirement Benefits Business	1,500,000,000		1,600,000,000
Reinsurance Recoverable Individual Life And Annuity Reinsurance	4,100,000,000		4,200,000,000
Ceded Reinsurance Recoverable Ongoing Operations	317,000,000
Number Of Reinsurers Ongoing Operations	70
Reserve Held For Ceded Reinsurance Recoverable Ongoing Operations	4,000,000
Reinsurance Recoverable Run Off Reinsurance	243,000,000
Reserve Held For Reinsurance Recoverable Run Off Reinsurance	$ 1,000,000
Percentage Of Reinsurance Recoverables Runoff Reinsurance Secured	94.00%