Note 9 - Net Income (Loss) Per Share - Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net income (loss)	$ 6,188	$ 1,644	$ 7,113	$ (1,636)
Basic (in shares)	13,973	13,163	13,917	13,102
Dilutive effect of incremental shares and share equivalents (in shares)	794	381	816
Diluted (in shares)	14,767	13,544	14,733	13,102
Net income (loss) per share:
Basic (in dollars per share)	$ 0.44	$ 0.12	$ 0.51	$ (0.12)
Diluted (in dollars per share)	$ 0.42	$ 0.12	$ 0.48	$ (0.12)