Investments (Other Invested Assets) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Document Period End Date	Mar. 31, 2020
Other invested assets	$ 2,542	$ 2,363
Limited Partner [Member]
Other invested assets	1,183	1,134
Equity Release Mortgages [Member]
Other invested assets	763	775
Derivatives
Other invested assets	252	117
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Other invested assets	235	260
Other
Other invested assets	$ 109	$ 77