Segment Information (Reconciliation Of Assets From Segments To Consolidated) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total assets	$ 298,147	$ 281,763
Annuities Segment [Member]
Segment Reporting Information [Line Items]
Total assets	145,458	144,721
Retirement Plan Services Segment [Member]
Segment Reporting Information [Line Items]
Total assets	35,736	37,072
Life Insurance Segment [Member]
Segment Reporting Information [Line Items]
Total assets	81,533	81,381
Group Protection Segment [Member]
Segment Reporting Information [Line Items]
Total assets	8,495	4,033
Other Operations [Member]
Segment Reporting Information [Line Items]
Total assets	$ 26,925	$ 14,556