Share capital (Narrative) (Details)	0 Months Ended		12 Months Ended						128 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended		0 Months Ended	12 Months Ended						17 Months Ended		12 Months Ended								0 Months Ended		12 Months Ended	5 Months Ended	12 Months Ended
	Dec. 05, 2014	Sep. 09, 2014 USD ($)	Nov. 30, 2014 USD ($)	Nov. 30, 2014 CAD	Nov. 22, 2013 CAD	Nov. 30, 2013 USD ($)	Nov. 30, 2013 CAD	Nov. 30, 2012 USD ($)	Nov. 30, 2014 USD ($)	Nov. 30, 2013 Non-Vested Options [Member] USD ($)	Dec. 05, 2014 Number of RSU's [Member]	Nov. 30, 2014 Number of RSU's [Member]	Apr. 30, 2012 Plan of Arrangement [Member] USD ($)	Sep. 09, 2014 Number of DSU's [Member]	Nov. 30, 2014 Number of DSU's [Member]	Nov. 30, 2014 Stock-based Compensation [Member] USD ($)	Nov. 30, 2013 Stock-based Compensation [Member] USD ($)	Nov. 30, 2014 NovaGold Arrangement Options [Member] USD ($)	Nov. 30, 2013 NovaGold Arrangement Options [Member] USD ($)	Nov. 30, 2012 NovaGold Arrangement Options [Member] USD ($)	Apr. 30, 2014 NovaGold Arrangement Options [Member] USD ($)	Nov. 30, 2014 NovaGold Arrangement Options [Member] Non-Vested Options [Member] CAD	Nov. 30, 2014 Private Placement [Member] USD ($)	Nov. 30, 2014 Approximations [Member] USD ($)	Nov. 30, 2013 Approximations [Member] USD ($)	Nov. 30, 2012 Approximations [Member] USD ($)	Nov. 30, 2013 Approximations [Member] Non-Vested Options [Member] USD ($)	Nov. 30, 2014 Minimum [Member]	Nov. 30, 2014 Minimum [Member] Private Placement [Member] USD ($)	Nov. 30, 2014 Maximum [Member]	Dec. 05, 2012 Employees [Member] Number of RSU's [Member]	Dec. 05, 2012 Director [Member] Number of DSU's [Member]	Nov. 30, 2014 Director [Member] Number of DSU's [Member]	May 31, 2014 Non-executive directors [Member]	Nov. 30, 2014 New Employees [Member] USD ($)	Nov. 30, 2013 New Employees [Member] USD ($)
Stock issued pursuant to employment agreement								76,005
Common stock committed for issuance													6,181,352		20,685
Contributed surplus			$ 124,000			$ 152,000			$ 124,000				$ 12,200,000
Common Stock, Shares Authorized
Stock options granted			1,620,000	1,620,000																	2,189,040														1,620,000	65,000
Stock options granted, weighted average exercise price				1.22	3.11		1.98											$ 1.15			$ 1.74														$ 0.44	$ 0.73
Stock based compensation, recovery																		20,000
Share-based payments			887,000			4,904,000		9,411,000								400,000	3,400,000							500,000	4,700,000	9,200,000
Non-vested stock options outstanding			1,741,666	1,741,666		168,332	168,332		1,741,666	698,338								721,415	1,709,503			5,556
Weighted average exercise price options outstanding			$ 1.11			$ 1.79			$ 1.11	$ 1.09								$ 5.06	$ 4.08			3.69
Stock option expense			0			0		316,000	316,000	800,000								10,000									200,000
Stock Issued on Vesting of Performance Share Units			14,166	14,166		16,586	16,586
Stock-based Compensation for NovaGold Arrangement Options																		70,000		200,000
Vesting terms																												0 years		2 years
Granted												0		186,650	242,723																1,295,500	750,000	56,073
Units vested											337,336
Percent of issued and outstanding shares threshold			10.00%	10.00%
Options cancelled, amount																									800,000
Stock options, cancelled					5,710,000
Aggregate intrinsic value, vested options			0			10,000		0	0									0	20,000	20,000
Aggregate intrinsic value, options exercised																		20,000	70,000	30,000
Common shares issued for vested RSUs	337,336
Percentage of annual retainer in DSUs to be distributed																																		50.00%
Vesting of deferred share units			154,373	154,373
Gross proceeds from Private Placement																							7,500,000
Per unit amount																							$ 1.15
Per share amount																							$ 1.60
Proceeds from private placement, net			7,231,000			0		0	7,231,000														7,200,000
General and administrative expense																													4,000,000
Program expenditures																													2,700,000
Additional expenses																													800,000
Cash payments owed to directors, cancelled		$ 207,000