Note 14 - Stockholders' Equity - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Nov. 30, 2022	Nov. 30, 2021
Stock-based compensation expense	$ 10,943	$ 8,253	$ 20,136	$ 17,670
Share-Based Payment Arrangement, Option [Member]
Stock-based compensation expense	20	1,939	624	4,695
Restricted Stock Units (RSUs) [Member]
Stock-based compensation expense	$ 10,923	$ 6,314	$ 19,512	$ 12,975