CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($)	Common Stock [Member]	Additional Paid in Capital [Member]	Accumulated Deficit [Member]	Total
Beginning balance at Dec. 31, 2017	$ 216,430	$ 516,351,405	$ (386,659,120)	$ 129,908,715
Beginning balance (in shares) at Dec. 31, 2017	216,429,642
Shares issued for exercise of options, net	$ 154	43,902		44,056
Shares issued for exercise of options, net (in shares)	154,632
Share-based compensation		1,751,358		1,751,358
Net loss			(24,401,829)	(24,401,829)
Ending balance at Mar. 31, 2018	$ 216,584	518,146,665	(411,060,949)	107,302,300
Ending balance (in shares) at Mar. 31, 2018	216,584,274
Beginning balance at Dec. 31, 2018	$ 240,463	616,559,938	(519,276,280)	$ 97,524,121
Beginning balance (in shares) at Dec. 31, 2018	240,462,439			240,462,439
Shares issued for exercise of options, net	$ 759	99,348		$ 100,107
Shares issued for exercise of options, net (in shares)	759,401
Share-based compensation		2,575,369		2,575,369
Net loss			(39,506,375)	(39,506,375)
Ending balance at Mar. 31, 2019	$ 241,222	$ 619,234,655	$ (558,782,655)	$ 60,693,222
Ending balance (in shares) at Mar. 31, 2019	241,221,840			241,221,840