Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative-effect Adjustment from Adoption of ASU 2020-06	Common Stock	Additional Paid-In Capital	Additional Paid-In Capital Cumulative-effect Adjustment from Adoption of ASU 2020-06	Accumulated Deficit	Accumulated Deficit Cumulative-effect Adjustment from Adoption of ASU 2020-06	Accumulated Other Comprehensive Income (loss)
Beginning balance at Dec. 31, 2019	$ 125,239		$ 22	$ 387,926		$ (262,743)		$ 34
Beginning balance, shares at Dec. 31, 2019			22,217
Issuance of common stock	10,159		$ 1	10,158
Issuance of common stock, shares			1,133
Stock-based compensation	25,675			25,675
Net loss	(51,923)					(51,923)
Other comprehensive loss	(31)							(31)
Ending balance at Dec. 31, 2020	109,119	$ (29,301)	$ 23	423,759	$ (32,743)	(314,666)	$ 3,442	3
Ending balance, shares at Dec. 31, 2020			23,350
Issuance of common stock	17,648		$ 2	17,646
Issuance of common stock, shares			1,387
Stock-based compensation	40,498			40,498
Induced conversion on 2019 Notes (Note 7)	(97,738)			(97,738)
Net loss	(51,260)					(51,260)
Other comprehensive loss	(42)							(42)
Ending balance at Dec. 31, 2021	(11,076)		$ 25	351,422		(362,484)		(39)
Ending balance, shares at Dec. 31, 2021			24,737
Issuance of common stock	15,416		$ 1	15,415
Issuance of common stock, shares			1,361
Stock-based compensation	42,443			42,443
Induced conversion on 2019 Notes (Note 7)	(5,681)			(5,681)
Net loss	(24,301)					(24,301)
Other comprehensive loss	(1,210)							(1,210)
Ending balance at Dec. 31, 2022	$ 15,591		$ 26	$ 403,599		$ (386,785)		$ (1,249)
Ending balance, shares at Dec. 31, 2022			26,098