Note 2 - Summary of Significant Accounting Policies - Calculation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net income	$ 2,322	$ 2,321	$ 6,470	$ 6,167
Weighted average shares outstanding (in shares)	58,774	56,974	58,213	56,915
Basic (in dollars per share)	$ 0.04	$ 0.04	$ 0.11	$ 0.11
Weighted average shares outstanding (including dilutive CSEs) (in shares)	59,774	58,314	59,338	58,213
Diluted (in dollars per share)	$ 0.04	$ 0.04	$ 0.11	$ 0.11