Basis of presentation (Details) - Discontinued Operations, Disposed of by Means Other than Sale, Spinoff shares in Millions	Oct. 31, 2024	May 31, 2023 shares
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		4
Retained ownership percentage		0.10
Number of retained shares (in shares)		5.7
Everus | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stock split, conversion ratio	4