Investments (Securities Pledged) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financial Instruments Owned and Pledged as Collateral [Line Items]
Financial Instruments Owned and Pledged as Collateral	$ 32,109	$ 140,810
Security Owned and Pledged as Collateral, Associated Liabilities, Carrying Value	33,169	143,880
Fixed Maturities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Financial Instruments Owned and Pledged as Collateral	32,109	140,810
Securities sold under agreements to repurchase
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Associated Liabilities, Carrying Value	0	68,904
Cash collateral for loaned securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Associated Liabilities, Carrying Value	$ 33,169	$ 74,976