Reinsurance (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Ceded Premiums And Fees [Abstract]
Individual life insurance and annuity business sold	$ 46,000,000	$ 49,000,000	$ 97,000,000	$ 96,000,000
Other	70,000,000	59,000,000	136,000,000	117,000,000
Total	116,000,000	108,000,000	233,000,000	213,000,000
Reinsurance Recoveries [Abstract]
Individual life insurance and annuity business sold	69,000,000	87,000,000	137,000,000	152,000,000
Other	42,000,000	46,000,000	96,000,000	93,000,000
Total	111,000,000	133,000,000	233,000,000	245,000,000
Reinsurance Text Details [Abstract]
Reinsurance Recoverable Retirement Benefits Business	1,500,000,000		1,500,000,000		1,600,000,000
Reinsurance Recoverable Individual Life And Annuity Reinsurance	4,100,000,000		4,100,000,000		4,200,000,000
Ceded Reinsurance Recoverable Ongoing Operations	305,000,000		305,000,000
Number Of Reinsurers Ongoing Operations	70		70
Reserve Held For Ceded Reinsurance Recoverable Ongoing Operations	4,000,000		4,000,000
Reinsurance Recoverable Run Off Reinsurance	187,000,000		187,000,000
Reserve Held For Reinsurance Recoverable Run Off Reinsurance	$ 1,000,000		$ 1,000,000
Percentage Of Reinsurance Recoverables Runoff Reinsurance Secured	92.00%		92.00%