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Short-term Debt (Details 2) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 19, 2022 | Oct. 21, 2022 | Mar. 18, 2022 | Dec. 31, 2021
--- | --- | --- | --- | --- | ---
Short-term Debt [Line Items] |  |  |  |  |
Short-term borrowings | $ 246,500 |  |  |  | $ 0
Term Loan Agreement [Member] | MDU Energy Capital |  |  |  |  |
Short-term Debt [Line Items] |  |  |  |  |
Short-term borrowings |  |  | $ 11,500 |  |
Ratio of total debt to total capitalization as specified in debt covenants |  |  | 70.00% |  |
Term Loan Agreement [Member] | Centennial Energy Holdings, Inc. |  |  |  |  |
Short-term Debt [Line Items] |  |  |  |  |
Short-term borrowings |  | $ 135,000 |  | $ 100,000 |
Ratio of total debt to total capitalization as specified in debt covenants |  | 65.00% |  | 65.00% |

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