Commitments and Contingencies (Details Textual)	12 Months Ended
	May 31, 2019 USD ($) Officers	May 31, 2018 USD ($)
Commitments and Contingencies (Textual)
Total rent expenses under all lease agreement	$ 388,000	$ 369,000
Number of executive officers | Officers	2
Description of agreement expiration date	2020 and 2022
Total remaining payments under these agreements	$ 1,495,000