CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	At The Market Offering	Underwritten Public Offering	Common Stock	Common Stock At The Market Offering	Common Stock Underwritten Public Offering	Additional Paid-in Capital	Additional Paid-in Capital At The Market Offering	Additional Paid-in Capital Underwritten Public Offering	Accumulated Deficit
Beginning Balance at Dec. 31, 2018	$ 78,744			$ 2			$ 175,201			$ (96,459)
Beginning Balance, Shares at Dec. 31, 2018				18,569,289
Net loss	(8,719)									(8,719)
Issuance of common stock upon exercise of stock options	18						18
Issuance of common stock upon exercise of stock options, Shares				11,141
Stock-based compensation	355						355
Ending Balance at Mar. 31, 2019	70,398			$ 2			175,574			(105,178)
Ending Balance, Shares at Mar. 31, 2019				18,580,430
Beginning Balance at Dec. 31, 2018	78,744			$ 2			175,201			(96,459)
Beginning Balance, Shares at Dec. 31, 2018				18,569,289
Net loss	(15,974)
Ending Balance at Jun. 30, 2019	63,469			$ 2			175,900			(112,433)
Ending Balance, Shares at Jun. 30, 2019				18,580,430
Beginning Balance at Mar. 31, 2019	70,398			$ 2			175,574			(105,178)
Beginning Balance, Shares at Mar. 31, 2019				18,580,430
Net loss	(7,255)									(7,255)
Stock-based compensation	326						326
Ending Balance at Jun. 30, 2019	63,469			$ 2			175,900			(112,433)
Ending Balance, Shares at Jun. 30, 2019				18,580,430
Beginning Balance at Dec. 31, 2019	51,365			$ 2			180,818			(129,455)
Beginning Balance, Shares at Dec. 31, 2019				19,418,955
Net loss	(7,092)									(7,092)
Issuance of common stock, net of commissions and issuance costs		$ 10,253						$ 10,253
Issuance of common stock net of commissions and issuance costs, Shares					1,502,892
Issuance of common stock upon exercise of stock options	154						154
Issuance of common stock upon exercise of stock options, Shares				30,143
Vesting of restricted stock	(84)						(84)
Vesting of restricted stock, Shares				29,890
Stock-based compensation	508						508
Ending Balance at Mar. 31, 2020	55,104			$ 2			191,649			(136,547)
Ending Balance, Shares at Mar. 31, 2020				20,981,880
Beginning Balance at Dec. 31, 2019	51,365			$ 2			180,818			(129,455)
Beginning Balance, Shares at Dec. 31, 2019				19,418,955
Net loss	$ (15,387)
Issuance of common stock upon exercise of stock options, Shares	115,671
Ending Balance at Jun. 30, 2020	$ 98,059			$ 3			242,898			(144,842)
Ending Balance, Shares at Jun. 30, 2020				27,287,997
Beginning Balance at Mar. 31, 2020	55,104			$ 2			191,649			(136,547)
Beginning Balance, Shares at Mar. 31, 2020				20,981,880
Net loss	(8,295)									(8,295)
Issuance of common stock, net of commissions and issuance costs			$ 50,148			$ 1			$ 50,147
Issuance of common stock net of commissions and issuance costs, Shares						6,220,589
Issuance of common stock upon exercise of stock options	561						561
Issuance of common stock upon exercise of stock options, Shares				85,528
Vesting of restricted stock	(80)						(80)
Stock-based compensation	621						621
Ending Balance at Jun. 30, 2020	$ 98,059			$ 3			$ 242,898			$ (144,842)
Ending Balance, Shares at Jun. 30, 2020				27,287,997