Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2021	$ 14,187	$ 1,334	$ 558,945	$ (546,092)
Balance (in shares) at Dec. 31, 2021		13,410
Exercise of stock options	6,533	$ 8	6,525
Exercise of stock options (in shares)		805
Stock-based compensation	71		71
Net loss	(1,544)			(1,544)
Balance at Dec. 31, 2022	19,247	$ 1,342	565,541	(547,636)
Balance (in shares) at Dec. 31, 2022		14,215
Exercise of stock options	$ 521	$ 1	520
Exercise of stock options (in shares)	136	136
Stock-based compensation	$ 160		160
Net loss	(1,181)			(1,181)
Balance at Dec. 31, 2023	$ 18,747	$ 1,343	$ 566,221	$ (548,817)
Balance (in shares) at Dec. 31, 2023		14,351