Retirement Plans (Narrative) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017 USD ($) plan
Defined Benefit Plan Disclosure [Line Items]
Number of retirement plans	7
Defined benefit plan, number	3
Defined contribution plan, number	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	2
Post-retirement benefit plan number	1
United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, number	1
Defined contribution plan, number	2
Defined benefit plans, estimated future employer contributions in current fiscal year | $	$ 244
Defined benefit plan, contributions by employer | $	$ 122
Active Defined Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, number	1
Frozen Defined Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, number	2
Salaried Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, number	8