Share capital - Stock options plans and changes (Details)	3 Months Ended
	Feb. 28, 2021 $ / shares shares
Balance - end of year, number of options | shares	11,520,277
Balance - end of year, weighted average exercise price | $ / shares	$ 1.90
Stock option
Balance - beginning of the year, number of options | shares	8,647,500
Balance - beginning of the year, weighted average exercise price | $ / shares	$ 1.88
Number of options, Granted | shares	3,374,150
Weighted average exercise price, Granted | $ / shares	$ 1.98
Number of options, Exercised | shares	(381,373)
Weighted average exercise price, Exercised | $ / shares	$ 1.97
Number of options, Cancelled | shares	(120,000)
Weighted average exercise price, Cancelled | $ / shares	$ 2.42
Balance - end of year, number of options | shares	11,520,277
Balance - end of year, weighted average exercise price | $ / shares	$ 1.90