Segment Information (Reconciliation Of Assets From Segments To Consolidated) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total assets	$ 334,761	$ 298,147
Annuities Segment [Member]
Segment Reporting Information [Line Items]
Total assets	167,443	145,458
Retirement Plan Services Segment [Member]
Segment Reporting Information [Line Items]
Total assets	40,184	35,736
Life Insurance Segment [Member]
Segment Reporting Information [Line Items]
Total assets	92,561	81,533
Group Protection Segment [Member]
Segment Reporting Information [Line Items]
Total assets	9,467	8,495
Other Operations [Member]
Segment Reporting Information [Line Items]
Total assets	$ 25,106	$ 26,925