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v3.23.1

Subsequent Events (Details 1) - USD ($) $ in Thousands |  | 3 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Apr. 21, 2023 | Mar. 31, 2023 | Mar. 31, 2022 | May 01, 2023 | Jan. 20, 2023 | Dec. 31, 2022
Short-Term Debt [Line Items] |  |  |  |  |  |
Repayment of short-term borrowings |  | $ 20,000 | $ 0 |  |  |
Short-term borrowings |  | 501,500 | $ 99,958 |  |  | $ 246,500
Term Loan Agreement | Intermountain Gas Company |  |  |  |  |  |
Short-Term Debt [Line Items] |  |  |  |  |  |
Repayment of short-term borrowings |  | $ 20,000 |  |  |  |
Short-term borrowings |  |  |  |  | $ 125,000 |
Ratio of total debt to total capitalization as specified in debt covenants |  |  |  |  | 65.00% |
Term Loan Agreement | Subsequent Event [Member] | Intermountain Gas Company |  |  |  |  |  |
Short-Term Debt [Line Items] |  |  |  |  |  |
Repayment of short-term borrowings | $ 30,000 |  |  |  |  |
Term Loan Agreement | Subsequent Event [Member] | MDU Resources Group [Member] |  |  |  |  |  |
Short-Term Debt [Line Items] |  |  |  |  |  |
Short-term borrowings |  |  |  | $ 75,000 |  |
Ratio of total debt to total capitalization as specified in debt covenants |  |  |  | 65.00% |  |

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