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FAIR VALUE MEASUREMENT OF FINANCIAL INSTRUMENTS - Narrative (Details) - USD ($) $ in Thousands, shares in Millions | 1 Months Ended | 3 Months Ended | 9 Months Ended
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Sep. 30, 2024 | Oct. 31, 2022 | Apr. 30, 2022 | Sep. 30, 2021 | Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |
Investments lockup period expiration (in years) | 3 years |  |  |  |  |  |  |
Gain (loss) resulting from the change in the fair value of investments |  |  |  |  |  | $ 5,600 |  | $ 3,500
Depository beneficial interests |  | 0.50% |  |  |  |  |  |
Convertible notes |  |  |  |  | $ 9,400 |  | $ 9,400 |
Convertible notes (in shares) |  |  |  |  | 0.5 |  | 0.5 |
Investment shares |  |  |  |  | 1.0 |  | 1.0 |
Unrealized gain on investments |  |  |  |  | $ (800) | 1,900 | $ 1,300 | 3,700
Debt Securities | Level 3 |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |
Included in earnings |  |  |  |  | 0 | 0 | 10,162 | (5)
Included in other comprehensive income (loss) |  |  |  |  | $ (280) | $ 0 | $ 383 | $ 0
Galileo Technologies | Convertible Debt |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  | 5.00% |  |  |  |  |
ADNOC Drilling |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |
Payments to acquire investments |  |  |  | $ 100,000 |  |  |  |
Investment balance (in shares) |  |  |  | 159.7 |  |  |  |
Investments lockup period (in years) |  |  |  | 3 years |  |  |  |
Sale of equity securities, number of shares sold |  |  |  |  |  |  | 159.7 |
Increase (decrease) in equity securities, FV-NI |  |  |  |  |  |  | $ 193,300 |
Gain (loss) resulting from the change in the fair value of investments |  |  |  |  |  |  | (12,400) |
Fair value of the investment |  |  |  |  |  |  | 8,400 |
Equity securities, FV-NI, transaction fee associated with sale of securities |  |  |  |  |  |  | $ 4,000 |
ADNOC Drilling | ADNOC Drilling |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |
Ownership percentage (as a percent) |  |  |  | 1.00% |  |  |  |
Tamboran Resources Limited |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |
Payments to acquire investments |  | $ 14,100 |  |  |  |  |  |
Investment shares acquired (in shares) |  | 106.0 |  |  |  |  |  |
Tamboran Resources Limited | Tamboran Resources Limited |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |
Ownership percentage (as a percent) |  |  |  |  | 6.10% |  | 6.10% |
Galileo Technologies |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |
Payments to acquire investments |  |  | $ 33,000 |  |  |  |  |
Fair Value, Nonrecurring |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |
Debt security investments | $ 300 |  |  |  | $ 200 |  | $ 200 |
Investment in Tamboran | 4,300 |  |  |  | 5,800 |  | 5,800 |
Fair Value, Nonrecurring | Geothermal Investments |  |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |
Investment in Tamboran | 25,800 |  |  |  | $ 14,100 |  | $ 14,100 |
Equity securities, fair value | 100 |  |  |  |  |  |  |
Equity securities | $ 25,700 |  |  |  |  |  |  |

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