CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - 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, 2020	$ 109,119	$ (29,301)	$ 23	$ 423,759	$ (32,743)	$ (314,666)	$ 3,442	$ 3
Beginning balance, shares at Dec. 31, 2020			23,350
Issuance of common stock	8,524		$ 1	8,523
Issuance of common stock, shares			702
Stock-based compensation	7,449			7,449
Net loss	(9,416)					(9,416)
Ending balance at Mar. 31, 2021	86,375		$ 24	406,988		(320,640)		3
Ending balance, shares at Mar. 31, 2021			24,052
Beginning balance at Dec. 31, 2020	109,119	$ (29,301)	$ 23	423,759	$ (32,743)	(314,666)	$ 3,442	3
Beginning balance, shares at Dec. 31, 2020			23,350
Net loss	(18,322)
Other comprehensive loss	1
Ending balance at Jun. 30, 2021	88,771		$ 24	418,289		(329,546)		4
Ending balance, shares at Jun. 30, 2021			24,254
Beginning balance at Mar. 31, 2021	86,375		$ 24	406,988		(320,640)		3
Beginning balance, shares at Mar. 31, 2021			24,052
Issuance of common stock	719			719
Issuance of common stock, shares			202
Stock-based compensation	10,582			10,582
Net loss	(8,906)					(8,906)
Other comprehensive loss	1							1
Ending balance at Jun. 30, 2021	88,771		$ 24	418,289		(329,546)		4
Ending balance, shares at Jun. 30, 2021			24,254
Beginning balance at Dec. 31, 2021	(11,076)		$ 25	351,422		(362,484)		(39)
Beginning balance, shares at Dec. 31, 2021			24,737
Issuance of common stock	4,611			4,611
Issuance of common stock, shares			483
Stock-based compensation	11,314			11,314
Net loss	(10,461)					(10,461)
Other comprehensive loss	(677)							(677)
Ending balance at Mar. 31, 2022	(6,289)		$ 25	367,347		(372,945)		(716)
Ending balance, shares at Mar. 31, 2022			25,220
Beginning balance at Dec. 31, 2021	(11,076)		$ 25	351,422		(362,484)		(39)
Beginning balance, shares at Dec. 31, 2021			24,737
Net loss	(21,984)
Other comprehensive loss	(1,187)
Ending balance at Jun. 30, 2022	(11,259)		$ 26	374,409		(384,468)		(1,226)
Ending balance, shares at Jun. 30, 2022			25,547
Beginning balance at Mar. 31, 2022	(6,289)		$ 25	367,347		(372,945)		(716)
Beginning balance, shares at Mar. 31, 2022			25,220
Issuance of common stock	1,885		$ 1	1,884
Issuance of common stock, shares			327
Stock-based compensation	10,859			10,859
Net loss	(11,523)					(11,523)
Other comprehensive loss	(510)							(510)
Induced conversion on 2019 Notes	(5,681)			(5,681)
Ending balance at Jun. 30, 2022	$ (11,259)		$ 26	$ 374,409		$ (384,468)		$ (1,226)
Ending balance, shares at Jun. 30, 2022			25,547