Consolidated Statements of Changes in Stockholders’ (Deficit) Equity - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss
Beginning balance (in shares) at Dec. 31, 2020		108,071,249
Beginning balance at Dec. 31, 2020	$ (18,006)	$ 11	$ 391,175	$ (404,629)	$ (4,563)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under Employee Stock Purchase Plan (in shares)		34,696
Issuance of common stock under Employee Stock Purchase Plan	72		72
Issuance of common stock upon exercise of options (in shares)		153,278
Issuance of common stock upon exercise of options	244		244
Issuance of vested restricted stock units (in shares)		10,937
Issuance of vested restricted stock units	0
Issuance of common stock through at-the-market offering, net (in shares)		4,706,844
Issuance of common stock through at-the-market offering, net	20,943		20,943
Stock-based compensation expense	1,780		1,780
Currency translation adjustment	(6)				(6)
Unrealized (losses) on marketable securities	(1)				(1)
Net income (loss)	(24,597)			(24,597)
Ending balance (in shares) at Mar. 31, 2021		112,977,004
Ending balance at Mar. 31, 2021	(19,571)	$ 11	414,214	(429,226)	(4,570)
Beginning balance (in shares) at Dec. 31, 2020		108,071,249
Beginning balance at Dec. 31, 2020	(18,006)	$ 11	391,175	(404,629)	(4,563)
Increase (Decrease) in Stockholders' Equity
Currency translation adjustment	5
Unrealized (losses) on marketable securities	(1)
Net income (loss)	(37,926)
Ending balance (in shares) at Sep. 30, 2021		115,443,500
Ending balance at Sep. 30, 2021	(18,731)	$ 12	428,371	(442,555)	(4,559)
Beginning balance (in shares) at Mar. 31, 2021		112,977,004
Beginning balance at Mar. 31, 2021	(19,571)	$ 11	414,214	(429,226)	(4,570)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of options (in shares)		242,278
Issuance of common stock upon exercise of options	425		425
Issuance of vested restricted stock units (in shares)		10,938
Issuance of vested restricted stock units	0
Issuance of common stock through at-the-market offering, net (in shares)		1,849,072
Issuance of common stock through at-the-market offering, net	8,563	$ 1	8,562
Stock-based compensation expense	1,783		1,783
Currency translation adjustment	12				12
Unrealized (losses) on marketable securities	1				1
Net income (loss)	4,565			4,565
Ending balance (in shares) at Jun. 30, 2021		115,079,292
Ending balance at Jun. 30, 2021	(4,222)	$ 12	424,984	(424,661)	(4,557)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under Employee Stock Purchase Plan (in shares)		24,098
Issuance of common stock under Employee Stock Purchase Plan	89		89
Issuance of common stock upon exercise of options (in shares)		1,936
Issuance of common stock upon exercise of options	5		5
Issuance of vested restricted stock units (in shares)		10,937
Issuance of vested restricted stock units	0
Issuance of common stock through at-the-market offering, net (in shares)		327,237
Issuance of common stock through at-the-market offering, net	1,389		1,389
Stock-based compensation expense	1,904		1,904
Currency translation adjustment	(1)				(1)
Unrealized (losses) on marketable securities	(1)				(1)
Net income (loss)	(17,894)			(17,894)
Ending balance (in shares) at Sep. 30, 2021		115,443,500
Ending balance at Sep. 30, 2021	$ (18,731)	$ 12	428,371	(442,555)	(4,559)
Beginning balance (in shares) at Dec. 31, 2021	123,622,965	123,622,965
Beginning balance at Dec. 31, 2021	$ 22,521	$ 12	457,391	(430,316)	(4,566)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under Employee Stock Purchase Plan (in shares)		81,057
Issuance of common stock under Employee Stock Purchase Plan	127		127
Issuance of common stock upon exercise of options (in shares)		11,262
Issuance of common stock upon exercise of options	21		21
Issuance of vested restricted stock units (in shares)		89,142
Issuance of vested restricted stock units	0
Issuance of common stock through at-the-market offering, net (in shares)		576,418
Issuance of common stock through at-the-market offering, net	1,675		1,675
Other financing fees	(79)		(79)
Stock-based compensation expense	2,753		2,753
Currency translation adjustment	(32)				(32)
Net income (loss)	28,778			28,778
Ending balance (in shares) at Mar. 31, 2022		124,380,844
Ending balance at Mar. 31, 2022	$ 55,764	$ 12	461,888	(401,538)	(4,598)
Beginning balance (in shares) at Dec. 31, 2021	123,622,965	123,622,965
Beginning balance at Dec. 31, 2021	$ 22,521	$ 12	457,391	(430,316)	(4,566)
Increase (Decrease) in Stockholders' Equity
Currency translation adjustment	65
Unrealized (losses) on marketable securities	(29)
Net income (loss)	$ 29,486
Ending balance (in shares) at Sep. 30, 2022	153,028,822	153,028,822
Ending balance at Sep. 30, 2022	$ 84,907	$ 15	490,252	(400,830)	(4,530)
Beginning balance (in shares) at Mar. 31, 2022		124,380,844
Beginning balance at Mar. 31, 2022	55,764	$ 12	461,888	(401,538)	(4,598)
Increase (Decrease) in Stockholders' Equity
Issuance of vested restricted stock units (in shares)		10,938
Issuance of vested restricted stock units	0
Issuance of common stock and common warrants (in shares)		27,428,572
Issuance of common stock and common warrants	21,480	$ 3	21,477
Other financing fees	79		79
Issuance of common stock, license agreement (in shares)		892,857
Issuance of common stock, license agreement	1,000		1,000
Stock-based compensation expense	2,564		2,564
Currency translation adjustment	118				118
Net income (loss)	8,601			8,601
Ending balance (in shares) at Jun. 30, 2022		152,713,211
Ending balance at Jun. 30, 2022	89,606	$ 15	487,008	(392,937)	(4,480)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under Employee Stock Purchase Plan (in shares)		39,820
Issuance of common stock under Employee Stock Purchase Plan	62		62
Issuance of common stock upon exercise of options (in shares)		59,928
Issuance of common stock upon exercise of options	135		135
Issuance of vested restricted stock units (in shares)		17,737
Issuance of vested restricted stock units	0
Issuance of common stock through at-the-market offering, net (in shares)		198,126
Issuance of common stock through at-the-market offering, net	446		446
Stock-based compensation expense	2,601		2,601
Currency translation adjustment	(21)				(21)
Unrealized (losses) on marketable securities	(29)				(29)
Net income (loss)	$ (7,893)			(7,893)
Ending balance (in shares) at Sep. 30, 2022	153,028,822	153,028,822
Ending balance at Sep. 30, 2022	$ 84,907	$ 15	$ 490,252	$ (400,830)	$ (4,530)