Statements Of Stockholders' Equity - USD ($)	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Total
Balance, Amount at Dec. 31, 2013	$ 19,311	$ 441,888,155	$ (205,999)	$ (453,403,462)	$ (11,701,995)
Balance, Shares at Dec. 31, 2013	19,311,390
Issuance of common stock and warrants, Amount	$ 879	2,852,794			2,853,673
Issuance of common stock and warrants, Shares	878,077
Share-based compensation		1,501,045			1,501,045
Grant of restricted shares, net of forfeitures, Shares	259
Restricted stock vestings, Amount	$ 291	(291)
Restricted stock vestings, Shares	291,148
Net loss				(5,202,441)	(5,202,441)
Balance, Amount at Dec. 31, 2014	$ 20,481	446,241,703	(205,999)	(458,605,903)	(12,549,718)
Balance, Shares at Dec. 31, 2014	20,480,874
Issuance of common stock and warrants, Amount	$ 809	940,545			941,354
Issuance of common stock and warrants, Shares	809,822
Share-based compensation		1,312,319			1,312,319
Restricted stock vestings, Amount	$ 242	(242)
Restricted stock vestings, Shares	241,775
Net loss				(7,352,775)	(7,352,775)
Employee stock purchase plan, Amount	$ 19	23,147			23,166
Employee stock purchase plan, Shares	18,702
Balance, Amount at Dec. 31, 2015	$ 21,551	$ 448,517,472	$ (205,999)	$ (465,958,678)	$ (17,625,654)
Balance, Shares at Dec. 31, 2015	21,551,173