Segment Information (Reconciliation Of Revenue From Segments To Consolidated) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	$ 3,381	$ 3,282	$ 6,685	$ 6,457
Annuities Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	991	926	1,981	1,835
Retirement Plan Services Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	270	270	543	541
Life Insurance Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	1,443	1,363	2,874	2,700
Group Protection Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	617	621	1,222	1,231
Other Operations [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	96	106	191	212
Excluded realized gain (loss), tax, reconciling item [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	(37)	(5)	(127)	(63)
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	$ 1	$ 1