Statements of Stockholders' Equity (Deficit) - USD ($)	Common Stock	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
Beginning Balance at Dec. 31, 2017	$ 8,006	$ 170,803,783	$ (204,988,674)	$ (34,176,885)
Beginning Balance, shares at Dec. 31, 2017	80,060,345
Issuance of common stock for services	$ 2	59,998	0	60,000
Issuance of common stock for services (Shares)	17,241
Options exercised, net	$ 25	400,734	0	400,759
Options exercised, net (Shares)	249,666
Warrants exercised, net	$ 568	2,699,651	0	2,700,219
Warrants exercised, net (Shares)	5,684,499
Stock-based compensation, net	$ 0	119,623	0	119,623
Net (loss) income	0	0	22,039,472	22,039,472
Ending Balance at Mar. 31, 2018	$ 8,601	174,083,789	(182,949,202)	(8,856,812)
Ending Balance, shares at Mar. 31, 2018	86,011,751
Beginning Balance at Dec. 31, 2017	$ 8,006	170,803,783	(204,988,674)	(34,176,885)
Beginning Balance, shares at Dec. 31, 2017	80,060,345
Net (loss) income				32,460,894
Ending Balance at Sep. 30, 2018	$ 10,659	174,753,999	(172,527,781)	2,236,877
Ending Balance, shares at Sep. 30, 2018	106,591,516
Beginning Balance at Mar. 31, 2018	$ 8,601	174,083,789	(182,949,202)	(8,856,812)
Beginning Balance, shares at Mar. 31, 2018	86,011,751
Options exercised, net	$ 10	235,641	0	235,651
Options exercised, net (Shares)	99,117
Warrants exercised, net	$ 21	159,655	0	159,676
Warrants exercised, net (Shares)	210,100
Stock-based compensation, net	$ 0	72,612	0	72,612
Net (loss) income	0	0	4,620,201	4,620,201
Ending Balance at Jun. 30, 2018	$ 8,632	174,551,697	(178,329,001)	(3,768,672)
Ending Balance, shares at Jun. 30, 2018	86,320,968
Warrants exercised, net	$ 27	109,197	0	109,224
Warrants exercised, net (Shares)	270,548
Stock-based compensation, net	$ 0	95,105	0	95,105
Issuance of common stock in connection with the public offering	$ 2,000	(2,000)	0	0
Issuance of common stock in connection with the public offering (in shares)	20,000,000
Net (loss) income	$ 0	0	5,801,220	5,801,220
Ending Balance at Sep. 30, 2018	$ 10,659	174,753,999	(172,527,781)	2,236,877
Ending Balance, shares at Sep. 30, 2018	106,591,516
Beginning Balance at Dec. 31, 2018	$ 11,094	176,227,510	(171,002,508)	5,236,096
Beginning Balance, shares at Dec. 31, 2018	110,941,516
Issuance of common stock for services	$ 14	59,986	0	60,000
Issuance of common stock for services (Shares)	136,362
Warrants exercised, net	$ 5	19,995	0	20,000
Warrants exercised, net (Shares)	50,000
Stock-based compensation, net	$ 0	27,555	0	27,555
Net (loss) income	0	0	(5,811,634)	(5,811,634)
Ending Balance at Mar. 31, 2019	$ 11,113	176,335,046	(176,814,142)	(467,983)
Ending Balance, shares at Mar. 31, 2019	111,127,878
Beginning Balance at Dec. 31, 2018	$ 11,094	176,227,510	(171,002,508)	5,236,096
Beginning Balance, shares at Dec. 31, 2018	110,941,516
Net (loss) income				(12,610,083)
Ending Balance at Sep. 30, 2019	$ 14,221	187,735,629	(183,612,591)	4,137,259
Ending Balance, shares at Sep. 30, 2019	142,207,862
Beginning Balance at Mar. 31, 2019	$ 11,113	176,335,046	(176,814,142)	(467,983)
Beginning Balance, shares at Mar. 31, 2019	111,127,878
Warrants exercised, net	$ 83	329,917	0	330,000
Warrants exercised, net (Shares)	825,000
Stock-based compensation, net	$ 0	72,800	0	72,800
Issuance of common stock in connection with the equity distribution agreement	$ 25	142,296	0	142,321
Issuance of common stock in connection with the equity distribution agreement (in shares)	254,984
Offering costs related to the issuance of common stock in connection with the equity distribution agreement	$ 0	(144,329)	0	(144,329)
Issuance of common stock in connection with the public offering	$ 3,000	10,753,878	0	10,756,878
Issuance of common stock in connection with the public offering (in shares)	30,000,000
Net (loss) income	$ 0	0	420,766	420,766
Ending Balance at Jun. 30, 2019	$ 14,221	187,489,608	(176,393,376)	11,110,453
Ending Balance, shares at Jun. 30, 2019	142,207,862
Stock-based compensation, net	$ 0	246,021	0	246,021
Net (loss) income	0	0	(7,219,215)	(7,219,215)
Ending Balance at Sep. 30, 2019	$ 14,221	$ 187,735,629	$ (183,612,591)	$ 4,137,259
Ending Balance, shares at Sep. 30, 2019	142,207,862