Income Taxes (Details 2) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2021	May 31, 2020	May 31, 2019
Current
U.S.	$ 100	$ 96	$ 128
Non U.S.	201	124	289
Current	301	220	417
Deferred
U.S.	(3,375)	(1,122)	(3,948)
Non U.S.	(1,430)	(446)	(25)
Deferred	(4,805)	(1,568)	(3,973)
Income tax benefit	$ (4,504)	$ (1,348)	$ (3,556)