Share capital - Authorized unlimited common shares, no par value (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Nov. 30, 2021
Class of Stock [Line Items]
Unlimited common shares authorized	Unlimited		Unlimited
Common Stock, No Par Value	$ 0		$ 0
Joint venture contribution	$ 51
Share capital
Class of Stock [Line Items]
Beginning balance, Number of shares	145,009,811
Beginning balance, Ascribed value	$ 180,820
Exercise of options, Number of shares	31,674	76,635
Exercise of options, Ascribed value	$ 50
Restricted share units, Number of shares	391,332
Restricted share units, Ascribed value	$ 650
Joint venture equity contribution (note 3(b)), Number of shares	31,469
Joint venture contribution	$ 51
Ending balance, Number of shares	145,464,286		145,009,811
Ending balance, Ascribed value	$ 181,571		$ 180,820