CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Follow-on Public Offering	Common Stock	Common Stock Follow-on Public Offering	Additional Paid-in Capital	Additional Paid-in Capital Follow-on Public Offering	Accumulated Deficit
Beginning Balance at Dec. 31, 2019	$ 62,140		$ 2		$ 116,162		$ (54,024)
Beginning Balance, Shares at Dec. 31, 2019			14,968
Stock-based compensation expense	2,755				2,755
Net loss	(5,093)						(5,093)
Issuance of shares upon vesting of restricted stock units, net of tax withholdings	(1,788)				(1,788)
Issuance of shares upon vesting of restricted stock units, net of tax withholdings, Shares			93
Ending Balance at Mar. 31, 2020	58,014		$ 2		117,129		(59,117)
Ending Balance, Shares at Mar. 31, 2020			15,061
Beginning Balance at Dec. 31, 2020	$ 109,880		$ 2		173,274		(63,396)
Beginning Balance, Shares at Dec. 31, 2020	17,150		17,150
Stock-based compensation expense	$ 7,366				7,366
Net loss	(3,565)						(3,565)
Issuance of common stock upon follow-on public offering net of underwriting discounts and commissions and other offering costs		$ 181,588				$ 181,588
Issuance of common stock upon follow-on public offering net of underwriting discounts and commissions and other offerings costs, Shares				1,500
Issuance of shares upon vesting of restricted stock units, net of tax withholdings, Shares			190
Ending Balance at Mar. 31, 2021	$ 295,269		$ 2		$ 362,228		$ (66,961)
Ending Balance, Shares at Mar. 31, 2021	18,840		18,840