Net Loss Per Share of Common Stock (Details) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share
Net loss—basic and diluted	$ (10,473,847)	$ (3,613,975)	$ (3,943,819)	$ (22,773,281)	$ (3,538,810)	$ (6,312,606)	$ (18,031,641)	$ (32,624,697)
Deemed dividend related to Warrant Exchange (Note 12)	0			0			(12,546,340)	0
Net loss to common stockholders	$ (10,473,847)			$ (22,773,281)			$ (30,577,981)	$ (32,624,697)
Shares used in calculating net loss per common share—basic and diluted (in shares)	141,591,218			6,411,308			92,764,157	5,839,840
Net loss per share of common share - basic and diluted (in USD per share)	$ (0.07)			$ (3.55)			$ (0.33)	$ (5.59)
Potentially dilutive securities
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares outstanding	5,138,294			68,150,339			5,138,294	68,150,339
Options to purchase common stock
Potentially dilutive securities
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares outstanding	4,268,277			500,933			4,268,277	500,933
Warrants
Potentially dilutive securities
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares outstanding	870,017			870,017			870,017	870,017
Warrants | Series A Warrants
Potentially dilutive securities
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares outstanding	0			8,771,928			0	8,771,928
Warrants | Series B Warrants
Potentially dilutive securities
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares outstanding	0			8,007,461			0	8,007,461
Warrants | Series C Warrants
Potentially dilutive securities
Potentially dilutive securities outstanding excluded from the computation of diluted weighted average shares outstanding	0			50,000,000			0	50,000,000