Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Feb. 29, 2024	Nov. 30, 2023	Aug. 31, 2023	Feb. 28, 2023	Nov. 30, 2022	Aug. 31, 2022	Feb. 29, 2024	Feb. 28, 2023	May 31, 2023
Summary of Significant Accounting Policies
Net loss	$ (11,920)	$ (9,563)	$ (11,571)	$ (13,702)	$ (26,495)	$ (20,991)	$ (33,054)	$ (61,188)
Accumulated deficit	(874,744)						(874,744)		$ (841,690)
Restricted cash	$ 6,619			$ 5,998			$ 6,619	$ 5,998	$ 6,507