Investments (Other Invested Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Other Investments [Abstract]
Other invested assets	$ 2,829	$ 2,363
Limited Partner [Member]
Other Investments [Abstract]
Other invested assets	1,367	1,134
Gain (Loss) on Derivatives [Member]
Other Investments [Abstract]
Other invested assets	140	117
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Other Investments [Abstract]
Other invested assets	289	260
Other [Member]
Other Investments [Abstract]
Other invested assets	98	77
Equity Release Mortgages [Member]
Other Investments [Abstract]
Other invested assets	$ 935	$ 775