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EMPLOYEE BENEFIT PLANS - Fair Value of Pension Plan Assets (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Jan. 16, 2025 | Sep. 30, 2024 | Sep. 30, 2023
--- | --- | --- | --- | ---
United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | $ 48,550 |  | $ 53,521 | $ 43,780
Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 35,128 | $ 33,200 | 0 |
Estimate of Fair Value Measurement | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 48,550 |  | 53,521 |
Estimate of Fair Value Measurement | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 35,152 |
Estimate of Fair Value Measurement | Short-term investments | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 201 |  | 3,369 |
Estimate of Fair Value Measurement | Mutual funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 48,322 |  | 50,060 |
Estimate of Fair Value Measurement | Domestic stock funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 2,218 |  | 5,223 |
Estimate of Fair Value Measurement | Bond funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 43,489 |  | 41,950 |
Estimate of Fair Value Measurement | International stock funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 2,615 |  | 2,887 |
Estimate of Fair Value Measurement | Oil and gas properties | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 27 |  | 92 |
Estimate of Fair Value Measurement | International equities | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 3,674 |
Estimate of Fair Value Measurement | Diversified Growth Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 4,636 |
Estimate of Fair Value Measurement | Gilts (UK government bonds) | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 1,359 |
Estimate of Fair Value Measurement | Corporate bonds | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 817 |
Estimate of Fair Value Measurement | Strategic Income Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 4,729 |
Estimate of Fair Value Measurement | Liability-Driven Investments (LDI) | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 9,365 |
Estimate of Fair Value Measurement | Absolute Return Credit Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 8,734 |
Estimate of Fair Value Measurement | Cash | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 1,838 |
Estimate of Fair Value Measurement | Level 1 | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 48,523 |  | 53,429 |
Estimate of Fair Value Measurement | Level 1 | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 6,871 |
Estimate of Fair Value Measurement | Level 1 | Short-term investments | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 201 |  | 3,369 |
Estimate of Fair Value Measurement | Level 1 | Mutual funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 48,322 |  | 50,060 |
Estimate of Fair Value Measurement | Level 1 | Domestic stock funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 2,218 |  | 5,223 |
Estimate of Fair Value Measurement | Level 1 | Bond funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 43,489 |  | 41,950 |
Estimate of Fair Value Measurement | Level 1 | International stock funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 2,615 |  | 2,887 |
Estimate of Fair Value Measurement | Level 1 | Oil and gas properties | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 1 | International equities | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 3,674 |
Estimate of Fair Value Measurement | Level 1 | Diversified Growth Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 1 | Gilts (UK government bonds) | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 1,359 |
Estimate of Fair Value Measurement | Level 1 | Corporate bonds | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 1 | Strategic Income Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 1 | Liability-Driven Investments (LDI) | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 1 | Absolute Return Credit Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 1 | Cash | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 1,838 |
Estimate of Fair Value Measurement | Level 2 | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 2 | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 28,281 |
Estimate of Fair Value Measurement | Level 2 | Short-term investments | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 2 | Mutual funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 2 | Domestic stock funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 2 | Bond funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 2 | International stock funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 2 | Oil and gas properties | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 2 | International equities | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 2 | Diversified Growth Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 4,636 |
Estimate of Fair Value Measurement | Level 2 | Gilts (UK government bonds) | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 2 | Corporate bonds | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 817 |
Estimate of Fair Value Measurement | Level 2 | Strategic Income Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 4,729 |
Estimate of Fair Value Measurement | Level 2 | Liability-Driven Investments (LDI) | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 9,365 |
Estimate of Fair Value Measurement | Level 2 | Absolute Return Credit Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 8,734 |
Estimate of Fair Value Measurement | Level 2 | Cash | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 3 | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 27 |  | 92 |
Estimate of Fair Value Measurement | Level 3 | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Short-term investments | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Mutual funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Domestic stock funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Bond funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 3 | International stock funds | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | 0 |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Oil and gas properties | United States |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets | $ 27 |  | 92 |
Estimate of Fair Value Measurement | Level 3 | International equities | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Diversified Growth Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Gilts (UK government bonds) | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Corporate bonds | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Strategic Income Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Liability-Driven Investments (LDI) | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Absolute Return Credit Fund | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | 0 |
Estimate of Fair Value Measurement | Level 3 | Cash | Foreign Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of pension plan assets |  |  | $ 0 |

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Data Type: | na
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