Segmented Information (Reconciliation Of Segment Assets To Consolidated Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment	$ 528,591	$ 580,701
Liabilities	387,971	412,291
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment	289,126	302,189
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment	106,924	126,396
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment	79,578	91,592
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment	$ 52,963	$ 60,524