Supplemental cash flow information (Schedule of Supplemental cash flow) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Supplemental Cash Flow Information [Abstract]
Interest paid, net of interest capitalized	$ 20,846	$ 16,387
Interest received	1,415	635
Net income taxes paid	13,855	43,249
Non-cash purchase of property, plant and equipment under finance lease	5,261	4,568
Non-cash right of use assets obtained in exchange for new lease obligations	$ 18,472	$ 9,451