Share capital (Narrative) (Details)	1 Months Ended		9 Months Ended				12 Months Ended
	Dec. 23, 2015 USD ($) shares	Apr. 30, 2012 USD ($) shares	Aug. 31, 2016 USD ($) $ / shares shares	Aug. 31, 2016 USD ($) $ / shares CAD / shares shares	Aug. 31, 2015 USD ($) shares	Aug. 31, 2015 USD ($) CAD / shares	Nov. 30, 2015 USD ($) $ / shares shares
Contributed surplus | $			$ 124,000	$ 124,000			$ 124,000
Stock options granted, weighted average exericse price | (per share)			$ 0.34	$ 0.44		CAD 0.61
Stock options granted			1,785,000
Stock options exercised			(364,969)
Stock options granted, weighted average exercise price | $ / shares			$ 0.39
Stock-based compensation | $			$ 544,000		$ 582,000
Non-vested stock options outstanding			6,408,381	6,408,381			5,288,350
Weighted average exercise price options outstanding | $ / shares			$ 0.52	$ 0.52			$ 0.58
Units vested	199,999
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	108,399
Aggregate intrinsic value, vested options | $			$ 490,000	$ 490,000	70,000	CAD 70,000
Aggregate intrinsic value, options exercised | $			$ 90,000
Cash paid upon vesting | $	$ 29,000
Vesting of deferred share units			218,795				232,878
Non-Vested Options [Member]
Non-vested stock options outstanding			2,346,133	2,346,133
Weighted average exercise price options outstanding | $ / shares			$ 0.45	$ 0.45
Number of RSU's [Member]
Granted	600,000		600,000
Plan of Arrangement [Member]
Common stock committed for issuance		6,181,352
Contributed surplus | $		$ 12,200,000
Number of DSU's [Member]
Common stock committed for issuance			20,685	20,685
Granted			212,768
Stock-based Compensation [Member]
Stock-based compensation | $			$ 220,000		120,000
NovaGold Arrangement Options [Member]
Issuance pursuant to Sunward Arrangement		46,578,078
Non-vested stock options outstanding			324,820	324,820			509,272
Weighted average exercise price options outstanding | $ / shares			$ 4.39	$ 4.39			$ 4.77
Aggregate intrinsic value, vested options | $			$ 0	$ 0	$ 0	CAD 0
Options expired			169,878
Approximations [Member] | Non-Vested Options [Member]
Stock option expense | $			$ 100,000
Minimum [Member]
Vesting terms			0 years
Maximum [Member]
Vesting terms			2 years
New Employees [Member]
Stock options granted			1,785,000		1,728,350
Stock options granted, weighted average exercise price | $ / shares			$ 0.13
Directors, Employees and Services Providers [Member]
Stock-based compensation | $			$ 330,000		$ 430,000