XML 113 R55.htm IDEA: XBRL DOCUMENT
v3.24.3

The following table discloses the components of interest expense associated with the Convertible Debentures. (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Jun. 30, 2024 | Jun. 30, 2023
Debt Disclosure [Abstract] |  |
Contractual interest | $ 279 | $ 225
Amortization of discount and issuance costs | 4,210 | 1,737
Total | $ 4,489 | $ 1,962

X
- Definition The element represents contractual interest. + References No definition available. + Details
Name: | niobf_ContractualInterest
Namespace Prefix: | niobf_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of amortization expense attributable to debt issuance costs. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1F -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481139/470-20-50-1F Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-28 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482925/835-30-45-3 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(8)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_AmortizationOfFinancingCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DebtDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest and debt related expenses associated with nonoperating financing activities of the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -SubTopic 20 -Topic 835 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483013/835-20-50-1 + Details
Name: | us-gaap_InterestAndDebtExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration