Note 12 - Net Loss Per Share - Calculation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Net loss	$ (1,330)	$ (687)	$ (710)	$ (2,691)	$ (3,114)	$ (2,082)	$ (2,096)	$ (424)	$ (5,418)	$ (7,716)
Basic weighted-average shares outstanding (in shares)									32,411	32,169
Effect of dilutive options and restricted stock units (in shares)
Diluted weighted-average shares outstanding (in shares)									32,411	32,169
Basic (in dollars per share)	$ (0.04)	$ (0.02)	$ (0.02)	$ (0.08)	$ (0.10)	$ (0.06)	$ (0.07)	$ (0.01)	$ (0.17)	$ (0.24)
Diluted (in dollars per share)	$ (0.04)	$ (0.02)	$ (0.02)	$ (0.08)	$ (0.10)	$ (0.06)	$ (0.07)	$ (0.01)	$ (0.17)	$ (0.24)