Segment Information (Premiums, Universal Life and Investment-Type Product Policy Fees and Other Revenues by Major Product Group) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total premiums, universal life and investment-type product policy fees and other revenues	$ 4,095	$ 4,346	$ 4,320
Annuity products
Segment Reporting Information [Line Items]
Total premiums, universal life and investment-type product policy fees and other revenues	2,522	2,662	2,729
Life insurance products
Segment Reporting Information [Line Items]
Total premiums, universal life and investment-type product policy fees and other revenues	1,561	1,677	1,587
Other products
Segment Reporting Information [Line Items]
Total premiums, universal life and investment-type product policy fees and other revenues	$ 12	$ 7	$ 4