Supplemental cash flow information (Schedule of Supplemental cash flow) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Supplemental Cash Flow Information [Abstract]
Interest paid, net of interest capitalized	$ 19,152	$ 14,914
Interest received	544	303
Net income taxes paid	4,067	23,681
Non-cash purchase of property, plant and equipment under finance lease	2,483	2,084
Non-cash right of use assets obtained (reassessed) in exchange for new lease obligations	$ 4,679	$ 6,234