Segmented information (Geographic Information of Revenue and location of assets) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 396,361	$ 389,050	$ 727,916	$ 662,305
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	183,391	204,588	390,805	395,118
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	98,690	97,990	147,168	133,633
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	55,467	47,430	102,643	73,768
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 58,813	$ 39,042	$ 87,300	$ 59,786