Share capital - Narrative (Details) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Aug. 31, 2021 USD ($) $ / shares shares	May 31, 2021 USD ($)	Feb. 28, 2021 USD ($)	Aug. 31, 2020 USD ($)	May 31, 2020 USD ($)	Feb. 29, 2020 USD ($)	Aug. 31, 2021 USD ($) $ / shares shares	Aug. 31, 2021 USD ($) $ / shares $ / shares shares	Aug. 31, 2020 USD ($) $ / shares shares	Aug. 31, 2020 USD ($) $ / shares	Aug. 31, 2021 $ / shares	Nov. 30, 2020 shares	Nov. 30, 2019 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, conversion							1
Common stock committed for issuance	144,451,485						144,451,485	144,451,485				144,137,850
Stock-based compensation | $	$ (409)	$ (524)	$ (2,148)	$ (1,064)	$ (770)	$ (1,196)
Non-vested stock options outstanding	11,118,316						11,118,316	11,118,316
Weighted average exercise price options outstanding | $ / shares	$ 1.94						$ 1.94	$ 1.94
Aggregate intrinsic value, vested options | $	$ 2,200			5,200			$ 2,200	$ 2,200	$ 5,200	$ 5,200
Aggregate intrinsic value, options exercised | $							$ 630		4,500
Share capital
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock committed for issuance	144,451,485						144,451,485	144,451,485				144,137,850	140,427,761
Nonvested Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested stock options outstanding	2,643,004						2,643,004	2,643,004
Weighted average exercise price options outstanding | $ / shares											$ 2.09
Stock option expense not yet recognized | $	$ 810						$ 810	$ 810
Period for recognition of stock compensation expense							2 years
DSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation | $	$ 30			40			$ 100		$ 430
Granted units							44,550
Outstanding grants	1,263,070						1,263,070	1,263,070				1,218,520
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding grants	0						0	0
Employees, consultants and directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted, expiration period							5 years
Stock options granted							3,374,150		4,095,000
Vesting period									2 years
Weighted-average exercise price | $ / shares								$ 2.00		$ 2.14
Stock options granted, weighted average fair value | $ / shares							$ 0.84		$ 0.90
Directors, employees and service providers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation | $	$ 380			$ 1,020			$ 2,980		$ 2,600