Segment Information (Reconciliation Of Revenue From Segments To Consolidated) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	$ 3,304	$ 3,176
Annuities Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	989	909
Retirement Plan Services Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	273	271
Life Insurance Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	1,432	1,337
Group Protection Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	605	610
Other Operations [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	95	106
Excluded realized gain (loss), tax, reconciling item [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	(91)	(58)
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