Cash flow information (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Supplemental Cash Flow Information [Abstract]
Interest, net	$ 49,407	$ 55,258
Income taxes paid, net	6,225	7,170
AFUDC borrowed	3,400	5,700
Right-of-use assets obtained in exchange for new operating lease liabilities	500	820	$ 1,787
Property, plant and equipment additions in accounts payable	$ 38,644	$ 45,981	$ 36,820