Segment Information (Premiums, Universal Life and Investment-Type Policy Fees and Other Revenues by Major Product Groups) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Insurance Services Revenue	$ 4,346	$ 4,320	$ 4,986
Annuity products
Segment Reporting Information [Line Items]
Insurance Services Revenue	2,662	2,729	3,411
Life insurance products
Segment Reporting Information [Line Items]
Insurance Services Revenue	1,677	1,587	1,552
Other products
Segment Reporting Information [Line Items]
Insurance Services Revenue	$ 7	$ 4	$ 23