Note 3 - Loss Per Share - Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended							9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Net loss	$ (1,446)	$ (2,577)	$ (2,856)	$ (1,702)	$ (1,303)	$ (3,074)	$ 319	$ (6,879)	$ (4,058)
Weighted–average shares outstanding (in shares)	20,152,029				20,076,021			20,152,029	19,684,004
Weighted–average shares outstanding with dilution (in shares)	20,152,029				20,076,021			20,152,029	19,684,004
Basic (in dollars per share)	$ (0.07)				$ (0.07)			$ (0.34)	$ (0.21)
Diluted (in dollars per share)	$ (0.07)				$ (0.07)			$ (0.34)	$ (0.21)
Share-based Payment Arrangement, Option [Member]
Dilutive effect of share-based awards (in shares)
Restricted Stock [Member]
Dilutive effect of share-based awards (in shares)