CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2012	$ 11,673,840	$ 4,835	$ 210,495,905	$ (217,328)	$ (198,609,572)
Balance (in shares) at Dec. 31, 2012		48,352,651
Net loss	(11,718,353)	$ 0	0	0	(11,718,353)
Foreign currency translation adjustments	(1,382)	0	0	(1,382)	0
Realization of cumulative translation adjustment	0
Issuance of common stock, net issuance costs	5,944,095	$ 388	5,943,707	0	0
Issuance of common stock, net issuance costs (in shares)		3,883,173
Share-based compensation - stock options	1,352,117	$ 0	1,352,117	0	0
Shares issued upon exercise of stock options	74,796	$ 7	74,789	0	0
Shares issued upon exercise of stock options (in shares)		61,756
Employee vesting of restricted shares	10,599	$ 0	10,599	0	0
Employee vesting of restricted shares (in shares)		6,666
Balance at Dec. 31, 2013	7,335,712	$ 5,230	217,877,117	(218,710)	(210,327,925)
Balance (in shares) at Dec. 31, 2013		52,304,246
Net loss	(9,955,395)	$ 0	0	0	(9,955,395)
Foreign currency translation adjustments	(10,818)	0	0	(10,818)	0
Realization of cumulative translation adjustment	0
Issuance of common stock, net issuance costs	17,686,095	$ 1,052	17,685,043	0	0
Issuance of common stock, net issuance costs (in shares)		10,520,454
Share-based compensation - stock options	1,649,994	$ 0	1,649,994	0	0
Shares issued upon exercise of stock options	455,840	$ 35	455,805	0	0
Shares issued upon exercise of stock options (in shares)		352,718
Shares issued upon exercise of warrants	1,107,064	$ 42	1,107,022	0	0
Shares issued upon exercise of warrants (in shares)		419,218
Employee vesting of restricted shares	5,653	$ 1	5,652	0	0
Employee vesting of restricted shares (in shares)		6,667
Balance at Dec. 31, 2014	18,274,145	$ 6,360	238,780,633	(229,528)	(220,283,320)
Balance (in shares) at Dec. 31, 2014		63,603,303
Net loss	(3,440,705)	$ 0	0	0	(3,440,705)
Foreign currency translation adjustments	336	0	0	336	0
Realization of cumulative translation adjustment	229,192	0	0	229,192	0
Share-based compensation - stock options	613,017	0	613,017	0	0
Shares issued upon exercise of stock options	973,132	$ 78	973,054	0	0
Shares issued upon exercise of stock options (in shares)		778,783
Balance at Dec. 31, 2015	$ 16,649,117	$ 6,438	$ 240,366,704	$ 0	$ (223,724,025)
Balance (in shares) at Dec. 31, 2015		64,382,086