Note 10 - Earnings Per Share - Computation of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
EARNINGS PER SHARE
Net income	$ 2,652	$ 1,962	$ 10,613	$ 6,883	$ 4,614	$ 17,496
Weighted average shares used to compute basic EPS (in shares)	42,704		40,869		42,232	40,737
Dilutive effect of share-based awards (in shares)			96			73
Weighted average shares used to compute diluted EPS (in shares)	42,704		40,965		42,232	40,810
Basic (in dollars per share)	$ 0.06		$ 0.26		$ 0.11	$ 0.43
Diluted (in dollars per share)	$ 0.06		$ 0.26		$ 0.11	$ 0.43
Antidilutive shares	937,424				937,424