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Discontinued operations - Schedule of Income and Expense Constituting Pretax Income (Loss) From Discontinued Operations (Details) - Knife River Corporation - Discontinued Operations, Disposed of by Means Other than Sale, Spinoff $ in Thousands | 3 Months Ended
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Mar. 31, 2023 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |
Operating revenues | $ 307,239
Operating expenses | 351,274
Operating loss | (44,035)
Other income | 493
Interest expense | 14,067
Loss from discontinued operations before income taxes | (57,609)
Income taxes | (12,087)
Discontinued operations, net of tax | $ (45,522)

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