CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Total
Balance at beginning at Dec. 31, 2018	$ 26	$ 213,453	$ (8)	$ (106,848)	$ 106,623
Balance at beginning (in shares) at Dec. 31, 2018	26,217,701
Increase (decrease) in Stockholders' Equity
Unrealized gain (loss) on marketable securities			24		24
Restricted shares forfeited during the period (in shares)	(2,237)
Exercise of stock options		13			13
Exercise of stock options (in shares)	1,983
Equity-based compensation expense		1,618			1,618
Net Loss				(10,755)	(10,755)
Balance at end at Mar. 31, 2019	$ 26	215,084	16	(117,603)	97,523
Balance at end (in shares) at Mar. 31, 2019	26,217,447
Balance at beginning at Dec. 31, 2018	$ 26	213,453	(8)	(106,848)	106,623
Balance at beginning (in shares) at Dec. 31, 2018	26,217,701
Increase (decrease) in Stockholders' Equity
Unrealized gain (loss) on marketable securities					66
Net Loss					(23,280)
Balance at end at Jun. 30, 2019	$ 29	258,996	58	(130,128)	128,955
Balance at end (in shares) at Jun. 30, 2019	29,230,330
Balance at beginning at Mar. 31, 2019	$ 26	215,084	16	(117,603)	97,523
Balance at beginning (in shares) at Mar. 31, 2019	26,217,447
Increase (decrease) in Stockholders' Equity
Unrealized gain (loss) on marketable securities			42		42
Sale of common shares, net of issuance costs	$ 3	42,019			42,022
Sale of common shares, net of issuance costs (in shares)	3,000,000
Exercise of stock options		79			79
Exercise of stock options (in shares)	12,883
Equity-based compensation expense		1,814			1,814
Net Loss				(12,525)	(12,525)
Balance at end at Jun. 30, 2019	$ 29	258,996	58	(130,128)	128,955
Balance at end (in shares) at Jun. 30, 2019	29,230,330
Balance at beginning at Dec. 31, 2019	$ 30	270,682	37	(157,848)	112,901
Balance at beginning (in shares) at Dec. 31, 2019	29,792,922
Increase (decrease) in Stockholders' Equity
Unrealized gain (loss) on marketable securities			197		197
Exercise of stock options		405			405
Exercise of stock options (in shares)	40,252
Equity-based compensation expense		2,214			2,214
Net Loss				(17,070)	(17,070)
Balance at end at Mar. 31, 2020	$ 30	273,301	234	(174,918)	98,647
Balance at end (in shares) at Mar. 31, 2020	29,833,174
Balance at beginning at Dec. 31, 2019	$ 30	270,682	37	(157,848)	112,901
Balance at beginning (in shares) at Dec. 31, 2019	29,792,922
Increase (decrease) in Stockholders' Equity
Unrealized gain (loss) on marketable securities					12
Net Loss					(36,351)
Balance at end at Jun. 30, 2020	$ 30	276,294	49	(194,199)	82,174
Balance at end (in shares) at Jun. 30, 2020	29,874,687
Balance at beginning at Mar. 31, 2020	$ 30	273,301	234	(174,918)	98,647
Balance at beginning (in shares) at Mar. 31, 2020	29,833,174
Increase (decrease) in Stockholders' Equity
Unrealized gain (loss) on marketable securities			(185)		(185)
Restricted shares forfeited during the period (in shares)	(42,010)
Exercise of stock options		598			598
Exercise of stock options (in shares)	83,523
Equity-based compensation expense		2,395			2,395
Net Loss				(19,281)	(19,281)
Balance at end at Jun. 30, 2020	$ 30	$ 276,294	$ 49	$ (194,199)	$ 82,174
Balance at end (in shares) at Jun. 30, 2020	29,874,687