Condensed Statements of Shareholders' Equity - USD ($)	Total	Cashless Warrants [Member]	January 2019 Financing Transaction [Member]	February 2019 Financing Transaction [Member]	January 2019 Financing Transaction Overallotment [Member]	March 2019 Financing Transaction [Member]	March 2, 2020 Financing Transaction [Member]	March 4, 2020 Financing Transaction [Member]	December 2019 Financing Transaction Overallotment [Member]	April 2020 Financing Transaction [Member]	Common Stock [Member]	Common Stock [Member] Cashless Warrants [Member]	Common Stock [Member] January 2019 Financing Transaction [Member]	Common Stock [Member] February 2019 Financing Transaction [Member]	Common Stock [Member] January 2019 Financing Transaction Overallotment [Member]	Common Stock [Member] March 2019 Financing Transaction [Member]	Common Stock [Member] March 2, 2020 Financing Transaction [Member]	Common Stock [Member] March 4, 2020 Financing Transaction [Member]	Common Stock [Member] December 2019 Financing Transaction Overallotment [Member]	Common Stock [Member] April 2020 Financing Transaction [Member]	SeriesA Convertible Preferred Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Cashless Warrants [Member]	Additional Paid-in Capital [Member] January 2019 Financing Transaction [Member]	Additional Paid-in Capital [Member] February 2019 Financing Transaction [Member]	Additional Paid-in Capital [Member] January 2019 Financing Transaction Overallotment [Member]	Additional Paid-in Capital [Member] March 2019 Financing Transaction [Member]	Additional Paid-in Capital [Member] March 2, 2020 Financing Transaction [Member]	Additional Paid-in Capital [Member] March 4, 2020 Financing Transaction [Member]	Additional Paid-in Capital [Member] December 2019 Financing Transaction Overallotment [Member]	Additional Paid-in Capital [Member] April 2020 Financing Transaction [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2018	$ 3,042,519										$ 46											$ 223,500,051										$ (220,457,578)
Beginning balance, shares at Dec. 31, 2018											462,917										4,417
Stock-based compensation expense	102,459																					102,459
Shares issued upon exercise of common stock warrants	4,748																					4,748
Shares issued upon exercise of common stock warrants, shares											598
Deemed dividends related to warrants downround provision																						99,743										(99,743)
Shares and warrants issued, net of issuance costs			$ 2,032,311	$ 6,602,735	$ 592,306	$ 7,553,793							$ 10	$ 62	$ 5	$ 59								$ 2,032,301	$ 6,602,673	$ 592,301	$ 7,553,734
Shares and warrants issued, net of issuance costs, shares													99,000	625,000	53,886	595,000
Shares issued upon conversion of preferred stock											$ 5											(5)
Shares issued upon conversion of preferred stock, shares											50,343										(2,278)
Net loss	(5,916,787)																															(5,916,787)
Ending balance at Mar. 31, 2019	14,014,084										$ 187											240,488,005										(226,474,108)
Ending balance, shares at Mar. 31, 2019											1,886,744										2,139
Beginning balance at Dec. 31, 2018	3,042,519										$ 46											223,500,051										(220,457,578)
Beginning balance, shares at Dec. 31, 2018											462,917										4,417
Deemed dividends related to warrants downround provision	99,743
Net loss	(19,424,558)
Ending balance at Sep. 30, 2019	7,705,458										$ 228											247,687,112										(239,981,882)
Ending balance, shares at Sep. 30, 2019											2,301,820										2,133
Beginning balance at Dec. 31, 2018	3,042,519										$ 46											223,500,051										(220,457,578)
Beginning balance, shares at Dec. 31, 2018											462,917										4,417
Net loss	(25,100,000)
Ending balance at Dec. 31, 2019	11,200,643										$ 547											256,917,285										(245,717,189)
Ending balance, shares at Dec. 31, 2019											5,473,848										2,133
Beginning balance at Mar. 31, 2019	14,014,084										$ 187											240,488,005										(226,474,108)
Beginning balance, shares at Mar. 31, 2019											1,886,744										2,139
Stock-based compensation expense	224,641																					224,641
Shares issued upon exercise of common stock warrants	4,845,722										$ 41											4,845,681
Shares issued upon exercise of common stock warrants, shares											414,944
Shares issued upon conversion of preferred stock, shares											132										(6)
Warrant inducement expense	1,831,116																					1,831,116
Net loss	(7,816,012)																															(7,816,012)
Ending balance at Jun. 30, 2019	13,099,551										$ 228											247,389,443										(234,290,120)
Ending balance, shares at Jun. 30, 2019											2,301,820										2,133
Stock-based compensation expense	297,669																					297,669
Net loss	(5,691,762)																															(5,691,762)
Ending balance at Sep. 30, 2019	7,705,458										$ 228											247,687,112										(239,981,882)
Ending balance, shares at Sep. 30, 2019											2,301,820										2,133
Beginning balance at Dec. 31, 2019	11,200,643										$ 547											256,917,285										(245,717,189)
Beginning balance, shares at Dec. 31, 2019											5,473,848										2,133
Stock-based compensation expense	142,964																					142,964
Shares issued upon exercise of common stock warrants	2,306,708										$ 70	$ 61										2,306,638	$ (61)
Shares issued upon exercise of common stock warrants, shares											696,140	608,000
Deemed dividends related to warrants downround provision																						2,774										(2,774)
Shares and warrants issued, net of issuance costs							$ 8,565,500	$ 6,093,561	$ 659,958								$ 230	$ 160	$ 19									$ 8,565,270	$ 6,093,401	$ 659,939
Shares and warrants issued, net of issuance costs, shares																	2,300,000	1,600,000	192,750
Warrant inducement expense	2,102,109																					2,102,109
Net loss	(8,341,338)																															(8,341,338)
Ending balance at Mar. 31, 2020	22,730,105										$ 1,087											276,790,319										(254,061,301)
Ending balance, shares at Mar. 31, 2020											10,870,738										2,133
Beginning balance at Dec. 31, 2019	11,200,643										$ 547											256,917,285										(245,717,189)
Beginning balance, shares at Dec. 31, 2019											5,473,848										2,133
Shares issued upon exercise of common stock warrants, shares		876,772
Deemed dividends related to warrants downround provision	2,774
Net loss	(19,708,975)
Ending balance at Sep. 30, 2020	21,353,297										$ 1,340											286,780,895										(265,428,938)
Ending balance, shares at Sep. 30, 2020											13,396,570										2,133
Beginning balance at Mar. 31, 2020	22,730,105										$ 1,087											276,790,319										(254,061,301)
Beginning balance, shares at Mar. 31, 2020											10,870,738										2,133
Stock-based compensation expense	194,236																					194,236
Shares issued upon exercise of common stock warrants	72,608										$ 2											72,606
Shares issued upon exercise of common stock warrants, shares											20,584
Shares and warrants issued, net of issuance costs										$ 9,577,297										$ 223											$ 9,577,074
Shares and warrants issued, net of issuance costs, shares																				2,230,000
Net loss	(6,489,303)																															(6,489,303)
Ending balance at Jun. 30, 2020	26,084,943										$ 1,312											286,634,235										(260,550,604)
Ending balance, shares at Jun. 30, 2020											13,121,322										2,133
Stock-based compensation expense	166,730																					166,730
Shares issued upon exercise of common stock warrants	22,388										$ 1	$ 27										22,387	$ (27)
Shares issued upon exercise of common stock warrants, shares											6,546	268,772
Costs related to previous financings	(42,430)																					(42,430)
Fractional shares adjustment upon one-for-ten reverse stock split, shares											(70)
Net loss	(4,878,334)																															(4,878,334)
Ending balance at Sep. 30, 2020	$ 21,353,297										$ 1,340											$ 286,780,895										$ (265,428,938)
Ending balance, shares at Sep. 30, 2020											13,396,570										2,133