Stock-Based Compensation (Details 1) - Stock Option [Member] - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, Beginning Balance	8,941,930	5,981,106	3,909,580
Options, Granted	3,861,425	3,781,666	2,382,500
Options, Exercised	(445,334)	(35,008)	(6,583)
Options, Expired	(338,529)	(483,332)
Options, Forfeited	(383,265)	(302,502)	(304,391)
Options, Ending Balance	11,636,227	8,941,930	5,981,106	3,909,580
Options, Exercisable	6,193,649
Weighted Average Exercise Price, Beginning Balance	$ 2.14	$ 2.01	$ 1.78
Weighted Average Exercise Price, Granted	0.98	2.37	2.36
Weighted Average Exercise Price, Exercised	1.83	1.16	0.58
Weighted Average Exercise Price, Expired	1.96	2.48
Weighted Average Exercise Price, Forfeited	2.26	1.91	1.93
Weighted Average Exercise Price, Ending Balance	1.77	$ 2.14	$ 2.01	$ 1.78
Weighted Average Exercise Price, Exercisable	$ 2.02
Weighted Average Remaining Contractual Life, Balance Outstanding	5 years 5 months 26 days	5 years 8 months 1 day	5 years 9 months 18 days	5 years 7 months 2 days
Weighted Average Remaining Contractual Life, Exercisable	4 years 5 months 26 days
Aggregate Intrinsic Value, Beginning Balance	$ 2,900,000	$ 685,000	$ 785,000
Aggregate Intrinsic Value, Exercised	137,488	44,000	8,000
Aggregate Intrinsic Value, Ending Balance	194,355	2,900,000	$ 685,000	$ 785,000
Aggregate Intrinsic Value, Exercisable	194,355
Grant date fair value of options granted	$ 3,091,000	$ 7,974,000
Weighted average grant date fair value	$ 0.8	$ 2.12