Discontinued Operations - Narrative (Details) $ in Thousands				1 Months Ended	12 Months Ended
	Oct. 31, 2024	May 31, 2023 shares	Apr. 25, 2023 USD ($)	Nov. 30, 2023 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Realized gain on tax-free exchange of the retained shares in Knife River					$ 0	$ 186,556	$ 0
Long-term debt					2,292,610	2,166,223
Repayments of long-term debt					$ 182,135	$ 568,883	$ 38,764
Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration]					Income from discontinued operations, net of tax	Income from discontinued operations, net of tax	Income from discontinued operations, net of tax
Knife River Corporation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Repayments of long-term debt			$ 825,000
Knife River Corporation | Revolving Credit Facility
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Line of credit facility, maximum borrowing capacity			350,000
Knife River Corporation | Term Loan Agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Debt instrument, face amount			275,000
Senior Notes | Knife River Corporation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-term debt			$ 425,000
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff | Knife River Corporation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pro rata distribution of shares, percentage		0.90
Stock split, conversion ratio		0.25
Retained ownership percentage		0.10
Number of retained shares (in shares) | shares		5,700,000
Realized gain on tax-free exchange of the retained shares in Knife River				$ 186,600
Separation of Knife River (in shares) | shares		538,921
Separation related costs					$ 41,700	$ 58,600	$ 11,500
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff | Knife River Corporation | Cash Received, TSA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued operation, amount of continuing cash flows after disposal					1,500	2,900
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff | Knife River Corporation | Cash Paid, TSA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued operation, amount of continuing cash flows after disposal					$ 159	$ 823
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff | Everus
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stock split, conversion ratio	0.25
Discontinued operation, period of continuing involvement					18 months
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff | Everus | Maximum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued operation, period of continuing involvement					2 years
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff | Everus | Cash Received, TSA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued operation, amount of continuing cash flows after disposal					$ 727
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff | Everus | Cash Paid, TSA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued operation, amount of continuing cash flows after disposal					$ 47