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, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
EARNINGS PER SHARE
Net income	$ 33,280	$ 41,471	$ 9,942	$ 4,143	$ 74,751	$ 14,085
Weighted average shares used to compute basic EPS (in shares)	44,271		44,184		44,226	43,816
Weighted average shares used to compute diluted EPS (in shares)	45,135		44,184		45,022	43,816
Basic (in dollars per share)	$ 0.75		$ 0.23		$ 1.69	$ 0.32
Diluted (in dollars per share)	$ 0.74		$ 0.23		$ 1.66	$ 0.32
Antidilutive shares			937,424			937,424
Options
EARNINGS PER SHARE
Dilutive effect of stock-based awards (in shares)	615				610
Restricted Stock Units
EARNINGS PER SHARE
Dilutive effect of stock-based awards (in shares)	249				186