Risks and Uncertainties (Details) - USD ($) $ in Thousands			1 Months Ended	4 Months Ended	12 Months Ended
	Nov. 03, 2020	Dec. 17, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Risks and Uncertainties [Abstract]
Cash and cash equivalents			$ 31,807	$ 49,326	$ 31,807	$ 49,326
Accumulated deficit			$ (186,257)	$ (130,474)	(186,257)	(130,474)
Funding raised						52,226
Procceds from issuance of debt					0	70,000
Net proceeds from initial public offering					6,215	39,317
Common Stock issued upon warrant exercises						1,821
Debt repayment					$ 22,500	$ 50,000
Number of shares callable by warrants (in shares)			2,000,000		2,000,000
Period of strike price calculated on weighted average closing price					30 days
Warrants issued to purchase common stock (in shares)					143,000
Public Offering [Member]
Risks and Uncertainties [Abstract]
Number of common shares issued (in shares)		8,050,000				8,050,000
Net proceeds from initial public offering		$ 37,835				$ 37,295
At-the-Market Facility [Member]
Risks and Uncertainties [Abstract]
Number of common shares issued (in shares)			930,993	0
Proceeds from issuance of common stock			$ 6,055
Remaining borrowing capacity available under ATM facility			18,472		$ 18,472
Monetization Agreement [Member]
Risks and Uncertainties [Abstract]
Upfront payment received	$ 40,000				40,000
Additional payment received through the achievement of first milestone	$ 10,000				10,000
Aggregate payments received			50,000		50,000
Maximum amount of payments receivable under agreement			125,000		125,000
Monetization Agreement [Member] | Maximum [Member]
Risks and Uncertainties [Abstract]
Contingent payments			75,000		75,000
Senior Secured Notes Due 2025 [Member]
Risks and Uncertainties [Abstract]
Cash and cash equivalents			$ 31,807		$ 31,807
Interest rate	12.50%		12.50%		12.50%
Procceds from issuance of debt	$ 4,000				$ 4,000	$ 13,110
Debt repayment	22,500				22,500
Notes payable outstanding	$ 70,000		$ 51,500		51,500
Additional borrowing capacity			$ 30,000		$ 30,000
Number of shares callable by warrants (in shares)			714,000		714,000
Senior Secured Notes Due 2025 [Member] | Maximum [Member]
Risks and Uncertainties [Abstract]
Additional borrowing capacity			$ 30,000		$ 30,000
Senior Secured Notes Due 2025 - First Additional Offering [Member]
Risks and Uncertainties [Abstract]
Additional borrowing capacity			$ 10,000		$ 10,000
Number of shares callable by warrants (in shares)			143,000		143,000
Senior Secured Notes Due 2025 - Second Additional Offering [Member]
Risks and Uncertainties [Abstract]
Additional borrowing capacity			$ 20,000		$ 20,000