XML 125 R73.htm IDEA: XBRL DOCUMENT
v3.23.3

Changes in the Smith Credit Agreement principal balance are as follows: (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Jun. 30, 2023 | Jun. 30, 2022
Related Party Transactions [Abstract] |  |
Beginning balance | $ 2,000 | $ 2,318
Amounts advanced | 1,130 |
Repayments | (3,130) | (318)
Balance, end of period |  | $ 2,000

X
- Definition The element represents amounts advanced. + References No definition available. + Details
Name: | niobf_AmountsAdvanced
Namespace Prefix: | niobf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from long-term debt by a related party. Related parties, include, but are not limited to, affiliates, owners or officers and their immediate families, and pension trusts. + References No definition available. + Details
Name: | us-gaap_ProceedsFromRepaymentsOfRelatedPartyDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of deposits held by the entity for a related party (entity, shareholder, employee). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(k)(1)) -URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 + Details
Name: | us-gaap_RelatedPartyDepositLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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