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Subsequent Events (Details) - USD ($) $ in Thousands | Jan. 20, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | ---
Subsequent Event [Line Items] |  |  |
Long-term debt |  | $ 2,841,425 | $ 2,741,900
Term Loan Agreement [Member] | Cascade Natural Gas [Member] | Subsequent Event [Member] |  |  |
Subsequent Event [Line Items] |  |  |
Long-term debt | $ 150,000 |  |
Ratio of total debt to total capitalization as specified in debt covenants | 65.00% |  |
Term Loan Agreement [Member] | Intermountain Gas Company | Subsequent Event [Member] |  |  |
Subsequent Event [Line Items] |  |  |
Long-term debt | $ 125,000 |  |
Ratio of total debt to total capitalization as specified in debt covenants | 65.00% |  |

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