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TRANSACTIONS - Joint Venture with Astron on the Donald Project (Details) $ in Thousands, $ in Millions |  |  | 3 Months Ended | 9 Months Ended | 12 Months Ended | 16 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jun. 30, 2025 USD ($) | Sep. 24, 2024 USD ($) | Sep. 30, 2024 USD ($) | Sep. 30, 2025 USD ($) | Sep. 30, 2024 USD ($) | Jun. 03, 2025 USD ($) | Sep. 30, 2025 USD ($) | Sep. 25, 2024 | Jun. 03, 2024 USD ($) | Jun. 03, 2024 AUD ($)
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |
Amount expected to be invested within the next year |  |  |  | $ 9,343 | $ 7,306 |  |  |  |  |
Variable interest entity, maximum loss exposure |  |  |  | $ 21,130 |  |  | $ 21,130 |  |  |
Shares issued for joint venture interests |  |  | $ 3,500 |  |  |  |  |  |  |
Donald Project Joint Venture |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |
Equity method, ownership percentage |  |  |  | 7.49% |  |  | 7.49% | 3.21% |  |
Astron Corporation Limited | Donald Project Joint Venture |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |
Equity method, ownership percentage |  |  |  | 92.51% |  |  | 92.51% |  |  |
Private Placement |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |
Shares issued for joint venture interests |  | $ 3,500 |  |  |  |  |  |  |  |
Private Placement | Maximum |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |
Value of common shares issued in transaction |  |  |  |  |  | $ 17,500 |  |  |  |
Variable Interest Entity, Not Primary Beneficiary |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |
Maximum right to invest |  |  |  |  |  |  |  |  | $ 120,900 | $ 183
Maximum possible ownership percentage |  |  |  |  |  | 49.00% |  |  |  |
Amount expected to be invested within the next year | $ 13,000 |  |  |  |  |  | $ 17,630 |  |  |

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