Note 6 - Net Income (Loss) Per-share - Reconciliation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net income	$ 81	$ 254
Weighted-average shares of common stock outstanding (in shares)	15,969	15,526
Basic net income per share (in dollars per share)	$ 0.01	$ 0.02
Plus interest expense on convertible debt		$ 2
	$ 81	$ 256
Dilutive options and warrants outstanding (in shares)	2,910
Effect of conversion of convertible notes (in shares)		13
Number of shares used in diluted per-share computation (in shares)	18,879	15,539
Diluted net income per share (in dollars per share)	$ 0	$ 0.02