Note 4 - Notes Receivable (Details Textual) $ in Thousands	Jul. 27, 2018 USD ($) yr	Nov. 30, 2020 USD ($)	Nov. 30, 2019 USD ($)	Nov. 30, 2018 USD ($)	Nov. 30, 2017 USD ($)
Financing Receivable, after Allowance for Credit Loss, Total		$ 96,016	$ 92,679	$ 89,459	$ 0
Note Receivable Upon Completion of Galore Creek Project Pre-feasibility [Member]
Financing Receivable, after Allowance for Credit Loss, Total	$ 75,000
Receivable Instrument, Term (Year)	3 years
Note Receivable Upon Completion of Galore Creek Project Pre-feasibility [Member] | Measurement Input, Expected Term [Member]
Notes Receivable, Measurement Input | yr	3
Note Receivable Upon Completion of Galore Creek Project Feasibility [Member]
Financing Receivable, after Allowance for Credit Loss, Total	$ 25,000
Receivable Instrument, Term (Year)	5 years
Note Receivable Upon Completion of Galore Creek Project Feasibility [Member] | Measurement Input, Expected Term [Member]
Notes Receivable, Measurement Input | yr	5
Note Receivable Upon Approval of Galore Creek Project Construction Plan [Member]
Financing Receivable, after Allowance for Credit Loss, Total	$ 75,000
Notes Receivable, Fair Value Disclosure	0	96,016
Financing Receivable, Accumulated Accretion		$ 7,618
Notes Receivable Upon Completion Of Galore Creek Project [Member]
Notes Receivable, Fair Value Disclosure	$ 88,398
Notes Receivable Upon Completion Of Galore Creek Project [Member] | Measurement Input, Discount Rate [Member]
Notes Receivable, Measurement Input	0.036