Segment Information (Reconciliation Of Revenue From Segments To Consolidated) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	$ 3,716	$ 3,411	$ 10,400	$ 9,869
Annuities Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	1,060	944	3,041	2,779
Retirement Plan Services Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	282	272	826	813
Life Insurance Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	1,727	1,446	4,600	4,146
Group Protection Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	570	598	1,792	1,829
Other Operations [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	96	103	287	315
Excluded realized gain (loss), tax, reconciling item [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	(18)	47	(146)	(15)
Amortization of deferred gain arising from reserve changes on business sold through reinsurance, pre-tax [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	1	$ 1	2	$ 2
Amortization Of DFEL Associated With Benefit Ratio Unlocking, Pre-Tax [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	$ (2)		$ (2)