Segment Information (Reconciliation of DAC VOBA Amortization From Segments to Consolidated) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amortization of DAC and VOBA, Net of Interest
Amortization of DAC and VOBA, net of interest	$ 1,320	$ 1,167	$ 962
Annuities Segment [Member]
Amortization of DAC and VOBA, Net of Interest
Amortization of DAC and VOBA, net of interest	427	347	402
Retirement Plan Services Segment [Member]
Amortization of DAC and VOBA, Net of Interest
Amortization of DAC and VOBA, net of interest	25	27	26
Life Insurance Segment [Member]
Amortization of DAC and VOBA, Net of Interest
Amortization of DAC and VOBA, net of interest	757	701	455
Group Protection Segment [Member]
Amortization of DAC and VOBA, Net of Interest
Amortization of DAC and VOBA, net of interest	$ 111	$ 92	$ 79