Summary of Cash Proceeds of Registered Offering (Detail)	3 Months Ended
Aug. 31, 2018 USD ($)
Stockholders Equity Note [Line Items]
Gross proceeds from sale of common stock	$ 10,000,000
Placement agent fees and expenses	1,010,000
Total net proceeds	$ 8,990,000

The cash inflow from the additional capital contribution to the entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration