Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common stock	Additional paid-in Capital	Accumulated other comprehensive income (loss)	Accumulated deficit
Balance at Dec. 31, 2019	$ 416,565		$ 2	$ 639,567	$ 216	$ (223,220)
Balance (in shares) at Dec. 31, 2019		1,969,797	15,429,154
Increase (Decrease) in Stockholders' Equity
Compensation expense related to stock options for services	4,846			4,846
Unrealized gain (loss) on marketable securities	199				199
Net loss	(36,135)					(36,135)
Balance at Mar. 31, 2020	385,475		$ 2	644,413	415	(259,355)
Balance (in shares) at Mar. 31, 2020		1,969,797	15,429,154
Balance at Dec. 31, 2020	$ 239,970		$ 2	665,385	47	(425,464)
Balance (in shares) at Dec. 31, 2020	15,508,146	1,969,797	15,508,146
Increase (Decrease) in Stockholders' Equity
Issuance of common shares in equity offering, excluding to related parties, net of transaction costs (in shares)			550,803
Issuance of common shares in equity offering, excluding to related parties, net of transaction costs	$ 66,616			66,616
Exercise of common stock options	478			478
Exercise of common stock options (in shares)			4,250
Compensation expense related to stock options for services	6,096			6,096
Unrealized gain (loss) on marketable securities	(61)				(61)
Net loss	(52,546)					(52,546)
Balance at Mar. 31, 2021	$ 260,553		$ 2	$ 738,575	$ (14)	$ (478,010)
Balance (in shares) at Mar. 31, 2021	16,063,199	1,969,797	16,063,199