Note 14 - Weighted Average Shares Outstanding and Net Income (Loss) Per Share (Details Textual) - $ / shares	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Nov. 30, 2019
Share Price, Potential Dilutive Effect (in dollars per share)		$ 31.47
The 2.75% Convertible Notes [Member]
Debt Instrument, Interest Rate, Stated Percentage	2.75%	2.75%	2.75%	2.75%	2.75%
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	636,000		580,000