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Note 4 - Notes Receivable (Details Textual)	Jul. 27, 2018 USD ($) yr	Feb. 28, 2021 USD ($)
Note Receivable Upon Completion of Galore Creek Project Pre-feasibility [Member]
Financing Receivable, after Allowance for Credit Loss, Total	$ 75,000,000
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	$ 25,000,000
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	$ 75,000,000
Notes Receivable, Fair Value Disclosure	0	$ 96,870
Financing Receivable, Accumulated Accretion		$ 8,472
Notes Receivable Upon Completion Of Galore Creek Project [Member]
Notes Receivable, Fair Value Disclosure	$ 88,398,000
Notes Receivable Upon Completion Of Galore Creek Project [Member] | Measurement Input, Discount Rate [Member]
Notes Receivable, Measurement Input	0.036

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- Definition

The amount of accumulated accretion associated with the financing receivable.

+ References

No definition available.

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Value of input used to measure notes receivable.

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- Definition

Fair value portion of an agreement for an unconditional promise by the maker to pay the holder a definite sum of money at a future date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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- Definition

Amount, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919230-210447

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-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522

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