Stock-Based Compensation (Details 1) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value	$ 2.36	$ 1.69	$ 2.21
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, Beginning Balance	3,909,580	4,453,746	2,979,010
Options, Granted	2,382,500	222,500	2,075,000
Options, Exercised	(6,583)	(291,666)	(374,851)
Options, Forfeited	(304,391)	(475,000)	(225,413)
Options, Ending Balance	5,981,106	3,909,580	4,453,746	2,979,010
Options, Exercisable	3,893,196
Weighted Average Exercise Price, Beginning Balance	$ 1.78	$ 1.78	$ 1.34
Weighted Average Exercise Price, Granted	$ 2.36	$ 1.69	$ 2.21
Weighted Average Exercise Price, Exercised	$ 0.58	$ 0.79	$ 0.34
Weighted Average Exercise Price, Forfeited	$ 1.93	$ 2.30	$ 2.37
Weighted Average Exercise Price, Ending Balance	$ 2.01	$ 1.78	$ 1.78	$ 1.34
Weighted Average Exercise Price, Exercisable	$ 1.85
Weighted Average Remaining Contractual Life, Balance Outstanding	5 years 9 months 18 days	5 years 7 months 2 days	6 years 5 months 5 days	6 years 4 days
Weighted Average Remaining Contractual Life, Exercisable	5 years 1 month 13 days
Aggregate Intrinsic Value, Beginning Balance	$ 785,000	$ 1,308,000	$ 0
Aggregate Intrinsic Value, Exercised	8,000	71,000	661,000
Aggregate Intrinsic Value, Ending Balance	685,000	785,000	1,308,000	0
Aggregate Intrinsic Value, Exercisable	685,000
Grant date fair value of options granted	$ 4,974,000	$ 350,000	$ 4,468,000
Weighted average grant date fair value	$ 2.09	$ 1.57	$ 2.15