Common Stock - Schedule of Stockholders Equity Deferred Share Unit Plan (Details)	3 Months Ended
	Jul. 31, 2020 $ / shares shares
Equity [Abstract]
Number of DSUs, outstanding | shares	699,183
Weighted Average Grant Date Fair Value Per DSU, Outstanding | $ / shares	$ 2.21
Number of DSUs, Granted | shares	0
Weighted Average Grant Date Fair Value Per DSU, Granted | $ / shares	$ 0
Number of DSUs, Cancelled | shares	(2,000)
Weighted Average Grant Date Fair Value Per DSU, Cancelled | $ / shares	$ 1.14
Number of DSUs, outstanding | shares	697,183
Weighted Average Grant Date Fair Value Per DSU, Outstanding | $ / shares	$ 2.21