Investments (Other Invested Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Other Investments [Abstract]
Other invested assets	$ 2,363	$ 1,915
Limited Partner [Member]
Other Investments [Abstract]
Other invested assets	1,134	965
Gain (Loss) on Derivatives [Member]
Other Investments [Abstract]
Other invested assets	117	180
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Other Investments [Abstract]
Other invested assets	260	198
Other [Member]
Other Investments [Abstract]
Other invested assets	77	96
Equity Release Mortgages [Member]
Other Investments [Abstract]
Other invested assets	$ 775	$ 476