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
Balances at end of period at Mar. 31, 2021	16,830		$ 11	311,342	(293,375)	(1,148)
Balances at end of period (in shares) at Mar. 31, 2021			10,941,000
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]
Issuance of common stock through equity distribution agreement, net of offering costs	3,025		$ 1	3,024
Issuance of common stock through equity distribution agreement, net of offering costs (in shares)			1,186,000
Issuance of common stock from vesting of restricted stock units (in shares)			205,000
Tax withholding related to vesting of restricted stock units	(111)			(111)
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	681			681
Net loss	(4,713)				(4,713)
Foreign currency translation adjustments	(36)					(36)
Balances at end of period at Jun. 30, 2021	14,677		$ 11	311,675	(295,876)	(1,133)
Balances at end of period (in shares) at Jun. 30, 2021			11,147,000
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 Mar. 31, 2021	16,830		$ 11	311,342	(293,375)	(1,148)
Balances at beginning of period (in shares) at Mar. 31, 2021			10,941,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from vesting of restricted stock units (in shares)			193,000
Tax withholding related to vesting of restricted stock units	(88)			(88)
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	405			405
Net loss	(2,501)				(2,501)
Foreign currency translation adjustments	15					15
Balances at end of period at Jun. 30, 2021	14,677		$ 11	311,675	(295,876)	(1,133)
Balances at end of period (in shares) at Jun. 30, 2021			11,147,000
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)			342,000
Tax withholding related to vesting of restricted stock units	(104)			(104)
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	1,707			1,707
Net loss	(7,373)				(7,373)
Foreign currency translation adjustments	41					41
Balances at end of period at Jun. 30, 2022	40,551		$ 16	353,018	(311,480)	(1,003)
Balances at end of period (in shares) at Jun. 30, 2022			15,887,000
Balances at beginning of period at Mar. 31, 2022	45,116		$ 15	352,248	(306,106)	(1,041)
Balances at beginning of period (in shares) at Mar. 31, 2022			15,543,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from vesting of restricted stock units (in shares)			331,000
Tax withholding related to vesting of restricted stock units	(75)			(75)
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	824			824
Net loss	(5,374)				(5,374)
Foreign currency translation adjustments	38					38
Balances at end of period at Jun. 30, 2022	$ 40,551		$ 16	$ 353,018	$ (311,480)	$ (1,003)
Balances at end of period (in shares) at Jun. 30, 2022			15,887,000

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