Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balances at Dec. 31, 2020	$ 139,832	$ 5	$ 415,824	$ 11	$ (276,008)
Balances (in shares) at Dec. 31, 2020		47,959
Issuance of common stock in connection with employee stock purchase plan	224		224
Issuance of common stock in connection with employee stock purchase plan (in shares)		38
Issuance of common stock in connection with exercise of stock options	146		146
Issuance of common stock in connection with exercise of stock options (in shares)		23
Issuance of common stock in connection with exercise of pre-funded warrants (in shares)		1,000
Stock-based compensation expense	1,757		1,757
Foreign currency translation adjustment	4			4
Unrealized gain (loss) on marketable securities	10			10
Net loss	(18,218)				(18,218)
Balances at Mar. 31, 2021	123,755	$ 5	417,951	25	(294,226)
Balances (in shares) at Mar. 31, 2021		49,020
Balances at Dec. 31, 2020	139,832	$ 5	415,824	11	(276,008)
Balances (in shares) at Dec. 31, 2020		47,959
Foreign currency translation adjustment	(4)
Unrealized gain (loss) on marketable securities	(5)
Net loss	(45,355)
Balances at Sep. 30, 2021	102,081	$ 5	423,437	2	(321,363)
Balances (in shares) at Sep. 30, 2021		49,306
Balances at Mar. 31, 2021	123,755	$ 5	417,951	25	(294,226)
Balances (in shares) at Mar. 31, 2021		49,020
Issuance of common stock in connection with exercise of stock options	33		33
Issuance of common stock in connection with exercise of stock options (in shares)		6
Stock-based compensation expense	2,080		2,080
Foreign currency translation adjustment	2			2
Unrealized gain (loss) on marketable securities	(16)			(16)
Net loss	(6,830)				(6,830)
Balances at Jun. 30, 2021	119,024	$ 5	420,064	11	(301,056)
Balances (in shares) at Jun. 30, 2021		49,026
Issuance of common stock in connection with employee stock purchase plan	230		230
Issuance of common stock in connection with employee stock purchase plan (in shares)		45
Issuance of common stock in connection with exercise of stock options	1,036		1,036
Issuance of common stock in connection with exercise of stock options (in shares)		235
Stock-based compensation expense	2,107		2,107
Foreign currency translation adjustment	(10)			(10)
Unrealized gain (loss) on marketable securities	1			1
Net loss	(20,307)				(20,307)
Balances at Sep. 30, 2021	102,081	$ 5	423,437	2	(321,363)
Balances (in shares) at Sep. 30, 2021		49,306
Balances at Dec. 31, 2021	83,941	$ 5	425,765	(20)	(341,809)
Balances (in shares) at Dec. 31, 2021		49,355
Issuance of common stock in connection with employee stock purchase plan	184		184
Issuance of common stock in connection with employee stock purchase plan (in shares)		65
Stock-based compensation expense	2,101		2,101
Foreign currency translation adjustment	(13)			(13)
Unrealized gain (loss) on marketable securities	(120)			(120)
Net loss	(24,436)				(24,436)
Balances at Mar. 31, 2022	61,657	$ 5	428,050	(153)	(366,245)
Balances (in shares) at Mar. 31, 2022		49,420
Balances at Dec. 31, 2021	83,941	$ 5	425,765	(20)	(341,809)
Balances (in shares) at Dec. 31, 2021		49,355
Foreign currency translation adjustment	(87)
Unrealized gain (loss) on marketable securities	(77)
Net loss	(64,993)
Balances at Sep. 30, 2022	67,555	$ 6	474,535	(184)	(406,802)
Balances (in shares) at Sep. 30, 2022		61,511
Balances at Mar. 31, 2022	61,657	$ 5	428,050	(153)	(366,245)
Balances (in shares) at Mar. 31, 2022		49,420
Issuance of common stock and pre-funded warrants in connection with public offering, net of offering costs	42,873	$ 1	42,872
Issuance of common stock and pre-funded warrants in connection with registered direct offering, net of offering costs (in shares)		10,753
Issuance of common stock in connection with exercise of pre-funded warrants (in shares)		1,000
Stock-based compensation expense	2,017		2,017
Foreign currency translation adjustment	(36)			(36)
Unrealized gain (loss) on marketable securities	(31)			(31)
Net loss	(22,323)				(22,323)
Balances at Jun. 30, 2022	84,157	$ 6	472,939	(220)	(388,568)
Balances (in shares) at Jun. 30, 2022		61,173
Issuance of common stock in connection with employee stock purchase plan	38		38
Issuance of common stock in connection with employee stock purchase plan (in shares)		87
Issuance of common stock in connection with registered direct offering, net of offering costs	(8)		(8)
Issuance of common stock in connection with exercise of pre-funded warrants (in shares)		251
Stock-based compensation expense	1,566		1,566
Foreign currency translation adjustment	(38)			(38)
Unrealized gain (loss) on marketable securities	74			74
Net loss	(18,234)				(18,234)
Balances at Sep. 30, 2022	$ 67,555	$ 6	$ 474,535	$ (184)	$ (406,802)
Balances (in shares) at Sep. 30, 2022		61,511