Note 14 - Net Income Per Share - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net income	$ 13,232	$ 15,641
Weighted average shares outstanding - basic (in shares)	22,516	22,661
Dilutive securities (in shares)	220	285
Weighted average shares outstanding- diluted (in shares)	22,736	22,946
Net income per share, basic (in dollars per share)	$ 0.59	$ 0.69
Net income per share, diluted (in dollars per share)	$ 0.58	$ 0.68