Segment Information (Schedule Of Revenue From Contracts With Customers) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 1,236
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	36
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,200
Fee Income [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	723
Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	513
Annuities Segment [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	906
Annuities Segment [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	24
Annuities Segment [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	882
Annuities Segment [Member] | Fee Income [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	534
Annuities Segment [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	372
Retirement Plan Services Segment [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	184
Retirement Plan Services Segment [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	5
Retirement Plan Services Segment [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	179
Retirement Plan Services Segment [Member] | Fee Income [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	167
Retirement Plan Services Segment [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	17
Life Insurance Segment [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	32
Life Insurance Segment [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	7
Life Insurance Segment [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	25
Life Insurance Segment [Member] | Fee Income [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	22
Life Insurance Segment [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	10
Group Protection Segment [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	114
Group Protection Segment [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	114
Group Protection Segment [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 114