Segment Information (Reconciliation Of Revenue From Segments To Consolidated) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Total revenues	$ 4,241	$ 3,764
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Excluded realized gain (loss), pre-tax	(55)	(391)
Annuities Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	1,021	1,088
Retirement Plan Services Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	293	289
Life Insurance Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	1,723	1,584
Group Protection Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	1,224	1,138
Other Operations [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 35	$ 56