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	$ 4,425	$ 3,965
Annuities Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	1,129	1,174
Retirement Plan Services Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	297	293
Life Insurance Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	1,821	1,700
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	38	57
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Excluded realized gain (loss), pre-tax	(75)	(400)
Amortization of DFEL associated with benefit ratio unlocking, pre-tax	$ (9)	$ 3