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Business Combinations - Additional Information (Details) - USD ($) $ in Millions |  |  | 12 Months Ended
--- | --- | --- | ---
Aug. 22, 2025 | Jul. 27, 2025 | Sep. 30, 2025
MoGas Pipeline [Member] |  |  |
Asset Acquisition, Contingent Consideration [Line Items] |  |  |
Payments to Acquire Businesses, Gross |  |  | $ 176.1
Tennessee Natural Gas [Member] |  |  |
Asset Acquisition, Contingent Consideration [Line Items] |  |  |
Payments to Acquire Businesses, Gross |  | $ 2,480.0 |
Tennessee Natural Gas [Member] | Senior Unsecured Bridge Facility [Member] |  |  |
Asset Acquisition, Contingent Consideration [Line Items] |  |  |
Line of credit facility maximum borrowing capacity | $ 2,480.0 |  |
Maturity term | 364 days |  |
Tennessee Natural Gas [Member] | Senior Unsecured Bridge Facility [Member] | Bridge Term Loan [Member] |  |  |
Asset Acquisition, Contingent Consideration [Line Items] |  |  |
Line of credit facility maximum borrowing capacity | $ 1,880.0 |  |
Tennessee Natural Gas [Member] | Senior Unsecured Bridge Facility [Member] | Delayed Draw Term Loan (DDTL) [Member] |  |  |
Asset Acquisition, Contingent Consideration [Line Items] |  |  |
Line of credit facility maximum borrowing capacity | $ 600.0 |  |
Tennessee Natural Gas [Member] | Secured Overnight Financing Rate (SOFR) [Member] | Senior Unsecured Bridge Facility [Member] |  |  |
Asset Acquisition, Contingent Consideration [Line Items] |  |  |
Debt instrument basis spread on variable rate | 1.375% |  |
Tennessee Natural Gas [Member] | Base Rate [Member] | Senior Unsecured Bridge Facility [Member] |  |  |
Asset Acquisition, Contingent Consideration [Line Items] |  |  |
Debt instrument basis spread on variable rate | 0.375% |  |

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