Segment Information (Reconciliation Of Revenue From Segments To Consolidated) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Total revenues	$ 3,928	$ 3,852	$ 7,692	$ 7,255
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Excluded realized gain (loss), pre-tax	(324)	(15)	(714)	(42)
Annuities Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	1,065	1,018	2,153	2,001
Retirement Plan Services Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	296	289	585	577
Life Insurance Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	1,686	1,575	3,269	3,123
Group Protection Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	1,155	937	2,293	1,490
Other Operations [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 50	$ 48	$ 106	$ 106