Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	At The Market Offering [Member]	Private Placement [Member]	Common Stock 0.00001 Par Value [Member]	Common Stock 0.00001 Par Value [Member] At The Market Offering [Member]	Common Stock 0.00001 Par Value [Member] Private Placement [Member]	Additional Paid-in Capital	Additional Paid-in Capital At The Market Offering [Member]	Additional Paid-in Capital Private Placement [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2020	$ 67,852						$ 575,811			$ (507,959)
Beginning balance, shares at Dec. 31, 2020				27,821,685
Net loss	(6,250)									(6,250)
Stock compensation expense	976						976
Vesting of restricted stock units	(2,613)						(2,613)
Vesting of restricted stock units, shares				246,737
Proceeds from employee stock option exercises	463						463
Proceeds from employee stock option exercises, shares				48,056
Proceeds from offering, net		$ 6,215						$ 6,215
Proceeds from offering, net, shares					305,182
Forfeiture of performance-based restricted stock, shares				(78,125)
Ending balance at Mar. 31, 2021	66,643						580,852			(514,209)
Ending balance, shares at Mar. 31, 2021				28,343,535
Beginning balance at Dec. 31, 2021	128,408						673,461			(545,053)
Beginning balance, shares at Dec. 31, 2021				33,218,115
Net loss	(19,484)									(19,484)
Stock compensation expense	1,828						1,828
Vesting of restricted stock units	(2,315)						2,315
Vesting of restricted stock units, shares				166,211
Proceeds from employee stock option exercises	$ 38						38
Proceeds from employee stock option exercises, shares				4,681
Proceeds from offering, net		$ 23,272	$ 49,864					$ 23,272	$ 49,864
Proceeds from offering, net, shares	737,288				737,288	1,791,986
Ending balance at Mar. 31, 2022	$ 181,611						$ 746,148			$ (564,537)
Ending balance, shares at Mar. 31, 2022				35,918,281