LEASES - RIGHT-OF-USE ASSETS AND LEASE LIABILITIES (Details) - USD ($) $ in Thousands |
Jun. 30, 2026 |
Sep. 30, 2025 |
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| Noncurrent Assets | ||
| Operating lease assets | $ 198,383 | $ 185,596 |
| Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] | Utility plant, at cost | Utility plant, at cost |
| Finance lease assets | $ 23,332 | $ 24,402 |
| Total lease assets | 221,715 | 209,998 |
| Current Liabilities | ||
| Operating lease liabilities | $ 5,534 | $ 4,388 |
| Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | Current maturities of long-term debt | Current maturities of long-term debt |
| Finance lease liabilities | $ 4,365 | $ 5,568 |
| Noncurrent Liabilities | ||
| Operating lease liabilities | $ 171,504 | $ 159,131 |
| Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Long-term debt | Long-term debt |
| Finance lease liabilities | $ 7,212 | $ 10,366 |
| Total lease liabilities | $ 188,615 | $ 179,453 |
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- Definition Lease, Liability No definition available.
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- Definition Lease, Right-of-Use Asset No definition available.
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- References No definition available.
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- Definition Present value of lessee's discounted obligation for lease payments from finance lease, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Indicates line item in statement of financial position that includes current finance lease liability. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Present value of lessee's discounted obligation for lease payments from finance lease, classified as noncurrent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Indicates line item in statement of financial position that includes noncurrent finance lease liability. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, after accumulated amortization, of right-of-use asset from finance lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Indicates line item in statement of financial position that includes finance lease right-of-use asset. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References No definition available.
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- References No definition available.
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as current. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of lessee's right to use underlying asset under operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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