Retirement Plans (Defined Contribution Plans) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Description of Defined Contribution Pension and Other Postretirement Plans	The Company sponsors six 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.
Defined Contribution Plan, Cost Recognized	$ 2,810	$ 2,553	$ 2,492
Salaried Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	2,425	2,151	2,107
Montreal Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	227	266	269
United Kingdom Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	$ 158	$ 136	$ 116

- Definition

Description of the terms and benefits provided by the employer's defined contribution plans. A defined contribution plan provides benefits in return for services rendered, provides an individual account for each participant, and has terms that specify how contributions to the individual's account are to be determined rather than the amount of benefits the individual is to receive. Under a defined contribution pension plan, the benefits a participant will receive depend solely on the amount contributed to the participant's account, the returns earned on investments of those contributions, and forfeitures of other participants' benefits that may be allocated to such participant's account. A description of the plan(s) including employee groups covered, the basis for determining contributions, and the nature and effects of significant matters affecting comparability of information for all periods presented.

+ References+ Details