Income Taxes - Components of Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Loss before tax expense:
U.S.	$ (28,495)	$ (31,595)	$ (166,984)
Non-U.S.	(1,454)	(4,457)	(1,151)
Income (loss) before tax expense	$ (29,949)	$ (36,052)	$ (168,135)