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Retirement Plans (Defined Contribution Plans) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Contribution Plan, Cost Recognized | $ 917 | $ 631 | $ 1,741 | $ 1,306
United States Benefit Plan [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Contribution Plan, Cost Recognized | 747 | 545 | 1,429 | 1,118
Canada Benefit Plan [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Contribution Plan, Cost Recognized | 55 | 56 | 114 | 120
United Kingdom Benefit Plans [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Contribution Plan, Cost Recognized | $ 115 | $ 30 | $ 198 | $ 68

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition The amount of the cost recognized during the period for defined contribution plans. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 + Details
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