Mineral properties and development costs - Mineral property expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Nov. 30, 2020	Nov. 30, 2019	Nov. 30, 2018
Mineral property expense	$ 1,545	$ 19,211	$ 16,490
Alaska, USA
Community	137	596	466
Drilling		5,194	4,545
Engineering	723	2,410	1,056
Environmental	99	611	806
Geochemistry and geophysics	12	1,259	1,253
Land and permitting	134	744	705
Project support	249	4,652	4,244
Other income		(13)	(20)
Wages and benefits	191	3,758	3,435
Mineral property expense	$ 1,545	$ 19,211	$ 16,490