Deferred Revenue (Details Narrative) - USD ($)	6 Months Ended
Nov. 30, 2019	May 31, 2019	Nov. 30, 2018
Revenue from Contract with Customer [Abstract]
Customer advances	$ 0		$ 3,280,500
Revenue recognition from customer advances	686,572
Unrecognized deferred revenue	$ 1,514,495	$ 2,201,067

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118944033&loc=SL49130531-203044

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130549-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=118944033&loc=SL49130532-203044

Name:	us-gaap_ContractWithCustomerLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant