Note 10 - Net Income (Loss) Per Common Share - Calculation of Diluted Shares (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Basic	$ 18,364	$ (19,161)
Diluted	$ (174)	$ (19,161)
Basic and diluted weighted average shares outstanding (in shares)	21,010,817	18,648,397
Basic earnings per share (in dollars per share)	$ 0.87	$ (1.03)
Diluted earnings per share (in dollars per share)	$ (0.01)	$ (1.03)