CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total		Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Balances at beginning of period at Dec. 31, 2020	$ 15,815		$ 10	$ 308,065	$ (291,163)	$ (1,097)
Balances at beginning of period (in shares) at Dec. 31, 2020			9,743,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock through equity distribution agreement, net of offering costs	41,679		$ 5	41,674
Issuance of common stock through equity distribution agreement, net of offering costs (in shares)			5,502,000
Issuance of common stock from vesting of restricted stock units (in shares)			233,000
Tax withholding related to vesting of restricted stock units	(269)			(269)
Issuance of common stock under employee stock purchase plan	16			16
Issuance of common stock under employee stock purchase plan (in shares)			13,000
Stock-based compensation expense	1,336			1,336
Net loss	(7,843)				(7,843)
Foreign currency translation adjustments	(10)					(10)
Balances at end of period at Sep. 30, 2021	50,724		$ 15	350,822	(299,006)	(1,107)
Balances at end of period (in shares) at Sep. 30, 2021			15,491,000
Balances at beginning of period at Dec. 31, 2020	15,815		$ 10	308,065	(291,163)	(1,097)
Balances at beginning of period (in shares) at Dec. 31, 2020			9,743,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(12,944)
Balances at end of period at Dec. 31, 2021	46,258	[1]	$ 15	351,394	(304,107)	(1,044)
Balances at end of period (in shares) at Dec. 31, 2021			15,532,000
Balances at beginning of period at Jun. 30, 2021	14,677		$ 11	311,675	(295,876)	(1,133)
Balances at beginning of period (in shares) at Jun. 30, 2021			11,147,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock through equity distribution agreement, net of offering costs	38,654		$ 4	38,650
Issuance of common stock through equity distribution agreement, net of offering costs (in shares)			4,316,000
Issuance of common stock from vesting of restricted stock units (in shares)			28,000
Tax withholding related to vesting of restricted stock units	(158)			(158)
Stock-based compensation expense	655			655
Net loss	(3,130)				(3,130)
Foreign currency translation adjustments	26					26
Balances at end of period at Sep. 30, 2021	50,724		$ 15	350,822	(299,006)	(1,107)
Balances at end of period (in shares) at Sep. 30, 2021			15,491,000
Balances at beginning of period at Dec. 31, 2021	46,258	[1]	$ 15	351,394	(304,107)	(1,044)
Balances at beginning of period (in shares) at Dec. 31, 2021			15,532,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from vesting of restricted stock units (in shares)			557,000
Tax withholding related to vesting of restricted stock units	(404)			(404)
Issuance of common stock under employee stock purchase plan	22		$ 1	21
Issuance of common stock under employee stock purchase plan (in shares)			13,000
Stock-based compensation expense	2,691			2,691
Net loss	(13,109)				(13,109)
Foreign currency translation adjustments	83					83
Balances at end of period at Sep. 30, 2022	35,541		$ 16	353,702	(317,216)	(961)
Balances at end of period (in shares) at Sep. 30, 2022			16,102,000
Balances at beginning of period at Jun. 30, 2022	40,551		$ 16	353,018	(311,480)	(1,003)
Balances at beginning of period (in shares) at Jun. 30, 2022			15,887,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from vesting of restricted stock units (in shares)			215,000
Tax withholding related to vesting of restricted stock units	(300)			(300)
Stock-based compensation expense	984			984
Net loss	(5,736)				(5,736)
Foreign currency translation adjustments	42					42
Balances at end of period at Sep. 30, 2022	$ 35,541		$ 16	$ 353,702	$ (317,216)	$ (961)
Balances at end of period (in shares) at Sep. 30, 2022			16,102,000

[1] Derived from the Company’s audited consolidated financial statements as of December 31, 2021.