Investments (Other Invested Assets) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Document Period End Date	Sep. 30, 2019
Other invested assets	$ 2,215,275	$ 1,915,297
Equity Release Mortgages [Member]
Other invested assets	669,981	475,905
Limited Partner [Member]
Other invested assets	1,059,025	965,094
Derivatives
Other invested assets	142,099	180,699
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Other invested assets	252,277	197,770
Other
Other invested assets	$ 91,893	$ 95,829