Share capital - Stock options outstanding (Details)	9 Months Ended
	Aug. 31, 2023 $ / shares shares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Number of outstanding options | shares	12,999,400
Weighted average years to expiry	2 years 5 months 15 days
Weighted average exercise price options outstanding	$ 2.16
Number of exercisable options | shares	10,867,643
Weighted average exercise price exercisable	$ 2.38
Number of unvested options | shares	2,131,757
$0.75 to $1.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price lower range limit	$ 0.75
Exercise price upper range limit	$ 1.00
Number of outstanding options | shares	3,230,000
Weighted average years to expiry	4 years 3 months 7 days
Weighted average exercise price options outstanding	$ 0.78
Number of exercisable options | shares	1,463,328
Weighted average exercise price exercisable	$ 0.78
Number of unvested options | shares	1,766,672
$2.01 to $2.50
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price lower range limit	$ 2.01
Exercise price upper range limit	$ 2.50
Number of outstanding options | shares	2,270,250
Weighted average years to expiry	2 years 6 months 21 days
Weighted average exercise price options outstanding	$ 2.27
Number of exercisable options | shares	1,905,165
Weighted average exercise price exercisable	$ 2.28
Number of unvested options | shares	365,085
$2.51 to $3.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price lower range limit	$ 2.51
Exercise price upper range limit	$ 3.00
Number of outstanding options | shares	6,041,650
Weighted average years to expiry	1 year 8 months 23 days
Weighted average exercise price options outstanding	$ 2.64
Number of exercisable options | shares	6,041,650
Weighted average exercise price exercisable	$ 2.64
Number of unvested options | shares	0
$3.01 to $3.50
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price lower range limit	$ 3.01
Exercise price upper range limit	$ 3.50
Number of outstanding options | shares	1,457,500
Weighted average years to expiry	1 year 3 months 21 days
Weighted average exercise price options outstanding	$ 3.03
Number of exercisable options | shares	1,457,500
Weighted average exercise price exercisable	$ 3.03
Number of unvested options | shares	0