Investments (Other Invested Assets) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Document Period End Date	Jun. 30, 2019
Other invested assets	$ 2,121,406	$ 1,915,297
Equity Release Mortgages [Member]
Other invested assets	641,611	475,905
Limited Partner [Member]
Other invested assets	1,008,571	965,094
Derivatives
Other invested assets	122,484	180,699
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Other invested assets	255,174	197,770
Other
Other invested assets	$ 93,566	$ 95,829