Summary of Fair Value Warrant Derivative Liability and Related Common Shares (Detail) - USD ($)		12 Months Ended
	Jun. 24, 2015	May 31, 2017		May 31, 2016	May 31, 2015	Sep. 15, 2016	Feb. 06, 2015	Sep. 26, 2014
Derivative [Line Items]
Beginning Balance		$ 0
Ending Balance		$ 3,014,667	[1]	$ 0
AVCP Convertible Notes
Derivative [Line Items]
Shares indexed					5,185,185		1,500,000	2,000,000
Change in fair value, shares					1,685,185
Beginning Balance				2,008,907	$ 0
Conversion of notes payable, shares	(5,185,185)
Change in fair value, amount				(646,505)	838,643
Conversion of notes payable June 24, 2015				(1,362,402)
Ending Balance					2,008,907
AVCP Convertible Notes | At September 26, 2014
Derivative [Line Items]
Inception date					767,038
AVCP Convertible Notes | At February 6, 2015
Derivative [Line Items]
Inception date					$ 403,226
Registered Direct Equity Offering | Investor Warrants Issued with Registered Direct Equity Offering
Derivative [Line Items]
Shares indexed		7,733,334				7,733,334
Beginning Balance		$ 0
Inception date		5,179,200
Ending Balance		$ 3,014,667		$ 0

[1] The Company did not have any assets or liabilities measured at fair value using Level 1 or 2 of the fair value hierarchy as of May 31, 2017 and May 31, 2016.