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Income Taxes (Narrative) (Details) - USD ($) $ in Millions | Dec. 31, 2017 | Dec. 31, 2016
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Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |
Deductible temporary differences for which no deferred tax asset is recognised | $ 77.8 | $ 100.7
Unrecognized tax liabilities | 6.1 | $ 24.2
Canada [Member] | Non-capital losses carried forward |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |
Unused tax losses for which no deferred tax asset recognised | 80.8 |
Mexico [Member] | Non-capital losses carried forward |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |
Unused tax losses for which no deferred tax asset recognised | 43.6 |
United States [Member] | Non-capital losses carried forward |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |
Unused tax losses for which no deferred tax asset recognised | 20.3 |
Turkey [Member] | Non-capital losses carried forward |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |
Unused tax losses for which no deferred tax asset recognised | $ 7.1 |

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