Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Supplemental Cash Flow Information [Line Items]
Interest, net	$ 108,242	$ 112,839	$ 49,036
Income taxes paid, net	43,572	12,162	(27,884)
AFUDC borrowed	11,000	10,000	2,200
Property, plant and equipment additions in accounts payable	36,820	46,364	34,886
Right-of-use assets obtained in exchange for new operating lease liabilities	1,787	2,265	1,324
Debt for equity exchange of retained shares in Knife River	0	293,239	0
Continuing And Discontinued Operations
Supplemental Cash Flow Information [Line Items]
Income taxes paid, net	$ 80,900	$ 62,500	$ 26,400