Share capital (Narrative) (Details)		1 Months Ended	9 Months Ended
	Dec. 15, 2016 shares	Dec. 23, 2016 USD ($) shares	Aug. 31, 2017 USD ($) $ / shares shares	Aug. 31, 2017 USD ($) $ / shares CAD / shares shares	Aug. 31, 2016 USD ($) shares	Aug. 31, 2016 USD ($) CAD / shares	Nov. 30, 2016 $ / shares shares
Stock options granted, weighted average exericse price | CAD / shares				CAD 0.72		CAD 0.44
Stock-based compensation | $			$ 603,000		$ 544,000
Non-vested stock options outstanding			7,212,627	7,212,627
Weighted average exercise price options outstanding | $ / shares			$ 0.56	CAD 0.56
Units vested		399,999
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		209,198
Aggregate intrinsic value, vested options | $			$ 2,800,000	CAD 2,800,000	490,000	CAD 490,000
Aggregate intrinsic value, options exercised | $			$ 150,000		90,000
Cash paid upon vesting | $		$ 90,000
Maximum [Member]
Vesting terms			2 years
Minimum [Member]
Vesting terms			0 years
Non-Vested Options [Member]
Non-vested stock options outstanding			1,405,843	1,405,843
Weighted average exercise price options outstanding | $ / shares			$ 0.48	CAD 0.48
Number of RSU's [Member]
Granted	600,000		600,000
Number of DSU's [Member]
Common stock committed for issuance			20,685	20,685
Stock-based compensation | $					$ 220,000
Granted			98,554
Class of Warrant or Right, Number of Securities Called by Warrants or Rights			3,447	3,447
Stock-based Compensation [Member]
Stock-based compensation | $			$ 290,000
NovaGold Arrangement Options [Member]
Non-vested stock options outstanding			0	0			312,195
Weighted average exercise price options outstanding | $ / shares			$ 0	CAD 0			$ 4.26
Approximationss [Member] | Non-Vested Options [Member]
Stock option expense | $			$ 100,000
New Employees [Member]
Stock options granted			1,695,000		1,785,000
Stock options granted, weighted average exercise price | $ / shares			$ 0.22
Directors, Employees and Services Providers [Member]
Stock-based compensation | $			$ 310,000		$ 330,000