Segmented Information (Geographic Information of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 303,429	$ 260,178
Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	303,429
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	183,573	135,563
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	31,531	65,809
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	54,785	34,574
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 33,540	$ 24,232