Retirement Plans (Narrative) (Details) - 3 months ended Mar. 31, 2017 $ in Thousands	Total	contract	item	USD ($)
Defined Benefit Plan Disclosure [Line Items]
Number of retirement plans | item			7
Defined Benefit Plan Number | item			3
Defined Contribution Plan Number		8	4
Description of Postemployment Benefits	The Company sponsors eight defined contribution plans for hourly and salaried employees across our domestic and international facilities. The following table summarizes the expense associated with the contributions made to these plans.
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year | $				$ 0
CANADA
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan Number | contract		2
Post-retirement benefit plan number | contract		1
UNITED KINGDOM
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Number | contract		1
Defined Contribution Plan Number | contract		2
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year | $				235
Defined Benefit Plan, Contributions by Employer | $				$ 59
Active Defined Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Number | item			1
Frozen Defined Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Number | item			2