Fair Value of Financial Instruments (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value of Financial Instruments (Textual) [Abstract]
Embedded Derivative, Gain (Loss) on Embedded Derivative Total	$ (5,076,000)	$ 2,529,000	$ (1,157,000)
Percentage Of Investment Portfolio Fair Value Pricing Services Or Index Price	90.00%	90.00%
Level 3 [Member]
Fair Value of Financial Instruments (Textual) [Abstract]
Embedded Derivative, Gain (Loss) on Embedded Derivative Total	$ (5,011,000)	$ 2,528