Segment Information (Reconciliation Of Revenue From Segments To Consolidated) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	$ 2,844	$ 2,710
Annuities Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	777	731
Retirement Plan Services Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	260	252
Life Insurance Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	1,245	1,227
Group Protection Segment [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	550	504
Other Operations [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	102	106
Excluded realized gain (loss), tax, reconciling item [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	(91)	(112)
Amortization of deferred gain (loss) on reinsurance related to reserve changes, tax, reconciling item [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues	1	1
Amortization Of DFEL Associated With Benefit Ratio Unlocking, Pre-Tax [Member]
Schedule Of Segment Reporting And Reconcilliation [Line Items]
Total revenues		$ 1