Derivative Instruments (Details 1) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Change in fair value of derivatives:
Net realized investment gains (losses)	[1]	$ (1,483)	$ 995	$ 0
Change in fair value of embedded derivatives:
Net realized investment gains (losses)		$ 2,529	$ (1,157)	$ 0

[1] Includes the gains or losses recognized at the expiration of the option term or early termination and the changes in fair value for open options.