Cash flow information (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Supplemental Cash Flow Information [Abstract]
Interest, net	$ 68,267	$ 74,677
Income taxes paid, net	27,491	14,385
AFUDC borrowed	5,400	8,400
Right-of-use assets obtained in exchange for new operating lease liabilities	1,344	1,104	$ 1,787
Property, plant and equipment additions in accounts payable	$ 53,653	$ 49,393	$ 36,820

Future cash outflow to pay for purchases of fixed assets that have occurred.

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