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Retirement Plans (Schedule of Costs of Retirement Plans) (Details) - Salaried Benefit Plan - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2017 | Jun. 30, 2016 | Jun. 30, 2017 | Jun. 30, 2016
Defined Contribution Plan Disclosure [Line Items] |  |  |  |
Defined Contribution Plan, Cost | $ 562 | $ 672 | $ 1,187 | $ 1,473
United States |  |  |  |
Defined Contribution Plan Disclosure [Line Items] |  |  |  |
Defined Contribution Plan, Cost | 410 | 445 | 861 | 1,137
Canada |  |  |  |
Defined Contribution Plan Disclosure [Line Items] |  |  |  |
Defined Contribution Plan, Cost | 54 | 67 | 113 | 118
United Kingdom |  |  |  |
Defined Contribution Plan Disclosure [Line Items] |  |  |  |
Defined Contribution Plan, Cost | $ 98 | $ 160 | $ 213 | $ 218

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- Definition Amount of cost for defined contribution plan. + 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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- 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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- Details
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