Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Cumulative Effect of Change in Accounting Principle [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member] Cumulative Effect of Change in Accounting Principle [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Dec. 31, 2018	$ 39,001		$ 1,597	$ 314,907	$ (276,800)		$ (703)
Balance, shares at Dec. 31, 2018			159,721,000
Issuance of common stock	7,781		$ 23	7,758
Issuance of common stock, shares			2,307,000
Common stock issued under equity compensation plan, net of shares withheld for taxes	(1,077)		$ 7	(1,084)
Common stock issued under equity compensation plan, net of shares withheld for taxes, shares			664,000
Exercise of options	674		$ 5	669
Exercise of options, shares			512,000
Share-based compensation	4,645			4,645
Net income (loss)	(6,722)				(6,722)
Other comprehensive income (loss)	(3)						(3)
Balance at Sep. 30, 2019	44,415	$ 116	$ 1,632	326,895	(283,406)	$ 116	(706)
Balance, shares at Sep. 30, 2019			163,204,000
Balance at Jun. 30, 2019	41,552		$ 1,630	325,075	(284,449)		(704)
Balance, shares at Jun. 30, 2019			163,053,000
Common stock issued under equity compensation plan, net of shares withheld for taxes	(13)		$ 1	(14)
Common stock issued under equity compensation plan, net of shares withheld for taxes, shares			9,000
Exercise of options	190		$ 1	189
Exercise of options, shares			142,000
Share-based compensation	1,645			1,645
Net income (loss)	1,043				1,043
Other comprehensive income (loss)	(2)						(2)
Balance at Sep. 30, 2019	44,415	$ 116	$ 1,632	326,895	(283,406)	$ 116	(706)
Balance, shares at Sep. 30, 2019			163,204,000
Balance at Dec. 31, 2019	54,500		$ 1,652	332,377	(278,827)		(702)
Balance, shares at Dec. 31, 2019			165,221,000
Common stock issued under equity compensation plan, net of shares withheld for taxes	(1,366)		$ 7	(1,373)
Common stock issued under equity compensation plan, net of shares withheld for taxes, shares			676,000
Exercise of options	1,512		$ 8	1,504
Exercise of options, shares			775,000
Share-based compensation	5,769			5,769
Net income (loss)	4,815				4,815
Other comprehensive income (loss)	11						11
Balance at Sep. 30, 2020	65,241		$ 1,667	338,277	(274,012)		(691)
Balance, shares at Sep. 30, 2020			166,672,000
Balance at Jun. 30, 2020	57,329		$ 1,661	335,372	(279,008)		(696)
Balance, shares at Jun. 30, 2020			166,085,000
Common stock issued under equity compensation plan, net of shares withheld for taxes	(16)			(16)
Common stock issued under equity compensation plan, net of shares withheld for taxes, shares			7,000
Exercise of options	1,123		$ 6	1,117
Exercise of options, shares			580,000
Share-based compensation	1,804			1,804
Net income (loss)	4,996				4,996
Other comprehensive income (loss)	5						5
Balance at Sep. 30, 2020	$ 65,241		$ 1,667	$ 338,277	$ (274,012)		$ (691)
Balance, shares at Sep. 30, 2020			166,672,000