Investments (Other Invested Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Other Investments [Abstract]
Other invested assets	$ 1,298,120	$ 1,198,319
Equity Securities [Member]
Other Investments [Abstract]
Other invested assets	125,862	126,860
Limited Partner [Member]
Other Investments [Abstract]
Other invested assets	567,697	446,604
Secured Debt [Member]
Other Investments [Abstract]
Other invested assets	45,422	164,309
Gain (Loss) on Derivatives [Member]
Other Investments [Abstract]
Other invested assets	256,178	216,966
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Other Investments [Abstract]
Other invested assets	197,547	140,344
Other [Member]
Other Investments [Abstract]
Other invested assets	$ 105,414	$ 103,236