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v3.25.3

Debt - Long-Term Debt (Details) - Senior Notes - Intermountain Gas Company - USD ($) $ in Millions | Nov. 14, 2025 | Jul. 15, 2025
--- | --- | ---
Long-term debt outstanding [Line Items] |  |
Face amount |  | $ 50.0
Interest rate, stated percentage |  | 6.39%
Proceeds from issuance of senior long-term debt |  | $ 25.0
Forecast | Subsequent Event |  |
Long-term debt outstanding [Line Items] |  |
Proceeds from issuance of senior long-term debt | $ 25.0 |

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