Derivatives (Embedded Derivatives) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded derivatives within liability host contracts	$ (36,327)	$ (23,740)
Ceded guaranteed minimum benefits | Premiums, reinsurance and other receivables
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded derivatives within asset host contracts	354,497	379,297
Direct guaranteed minimum benefits | Policyholder account balances
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded derivatives within liability host contracts	(36,258)	(23,740)
Fixed annuities with equity indexed returns | Policyholder account balances
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded derivatives within liability host contracts	$ 0	$ 0