Condensed Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income(Loss)	Accumulated Deficit
Balance, beginning (in shares) at Dec. 31, 2021		42,457,471
Balance, beginning at Dec. 31, 2021	$ 142,864		$ 536,362		$ (393,498)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued upon exercises of stock options (in shares)	36,500	36,500
Shares issued upon exercises of stock options	$ 134		134
Unrealized gain on available-for-sale securities	0
Stock-based compensation	2,446		2,446
Net loss	(15,351)				(15,351)
Balance, ending (in shares) at Mar. 31, 2022		42,493,971
Balance, ending at Mar. 31, 2022	130,093		538,942	$ 0	(408,849)
Balance, beginning (in shares) at Dec. 31, 2022		42,648,346
Balance, beginning at Dec. 31, 2022	$ 94,331		545,407	(21)	(451,055)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued upon exercises of stock options (in shares)	0
Shares issued upon vesting of restricted stock units (in shares)		170,000
Unrealized gain on available-for-sale securities	$ 39			39
Stock-based compensation	1,191		1,191
Net loss	(14,204)				(14,204)
Balance, ending (in shares) at Mar. 31, 2023		42,818,346
Balance, ending at Mar. 31, 2023	$ 81,357		$ 546,598	$ 18	$ (465,259)