Segment Information (Reconciliation Of Revenue From Segments To Consolidated) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Total revenues	$ 4,227	$ 4,039	$ 11,918	$ 11,295
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Excluded realized gain (loss), pre-tax	(268)	(107)	(981)	(149)
Annuities Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	1,024	1,031	3,177	3,032
Retirement Plan Services Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	293	290	877	867
Life Insurance Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	1,995	1,647	5,264	4,770
Group Protection Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	1,136	1,128	3,429	2,617
Other Operations [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 47	$ 50	$ 152	$ 158