Share capital - Stock options plans and changes (Details)	12 Months Ended
	Nov. 30, 2020 $ / shares shares	Nov. 30, 2020 $ / shares shares
Balance - end of year, number of options | shares	8,647,500	8,647,500
Balance - end of year, weighted average exercise price | $ / shares	$ 2.39
Stock option
Balance - beginning of the year, number of options | shares	9,205,600	9,205,600
Balance - beginning of the year, weighted average exercise price | $ / shares		$ 1.11
Number of options, Granted | shares	4,445,000	4,445,000
Weighted average exercise price, Granted | $ / shares		$ 2.15
Number of options, Exercised | shares	(4,263,100)	(4,263,100)
Weighted average exercise price, Exercised | $ / shares		$ 0.51
Number of options, Cancelled | shares	(740,000)	(740,000)
Weighted average exercise price, Cancelled | $ / shares		$ 2.27
Balance - end of year, number of options | shares	8,647,500	8,647,500
Balance - end of year, weighted average exercise price | $ / shares		$ 1.84