Stock Based Compensation (Details) - Stock option activity (Employee Stock Option [Member], USD $)	0 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Stock Option [Member]
Stock Based Compensation (Details) - Stock option activity [Line Items]
Outstanding at December 31, 2011	1,814,956	1,944,108	2,089,970
Outstanding at December 31, 2011	$ 6.39	$ 6.06	$ 5.99
Outstanding at December 31, 2011	7 years 36 days	5 years 255 days	6 years 255 days	6 years 146 days
Options Expired, Number of shares		(106,968)	(28,000)	(22,000)
Options Expired, Weighted-Average Exercise Price		$ 12.88	$ 11.75	$ 17.62
Granted				297,014
Granted				$ 4.43
Options outstanding, Number of shares		1,371,354	1,944,108	2,089,970
Options outstanding, Weighted-Average Exercise Price		$ 5.97	$ 6.06	$ 5.99
Options outstanding, Weighted-Average Remaining Contractual Term	7 years 36 days	5 years 255 days	6 years 255 days	6 years 146 days
Options outstanding, Aggregate Intrinsic Value
Exercisable at December 31, 2014		1,212,336
Exercisable at December 31, 2014		$ 6.24
Exercisable at December 31, 2014		5 years 146 days
Exercisable at December 31, 2014
Exercised			(35,246)
Exercised			$ 3.16
Options Forfeited, Number of shares		(465,786)	(82,616)
Options Forfeited, Weighted-Average Exercise Price		$ 4.76	$ 3.7