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v2.4.1.9

Income Taxes (Details 2) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Income Tax Disclosure [Abstract] |  |  |
Equity Method Investment, Summarized Financial Information, Income Tax |  | $ 15.2 gmt_EquityMethodInvestmentSummarizedFinancialInformationIncomeTax | $ 9.2 gmt_EquityMethodInvestmentSummarizedFinancialInformationIncomeTax
Current |  |  |
Federal | 0.7 us-gaap_CurrentFederalTaxExpenseBenefit | 1.4 us-gaap_CurrentFederalTaxExpenseBenefit | (8.8)us-gaap_CurrentFederalTaxExpenseBenefit
State and local | 0.6 us-gaap_CurrentStateAndLocalTaxExpenseBenefit | 0 us-gaap_CurrentStateAndLocalTaxExpenseBenefit | 2.5 us-gaap_CurrentStateAndLocalTaxExpenseBenefit
Current domestic taxes | 1.3 gmt_CurrentDomesticTaxExpenseBenefit | 1.4 gmt_CurrentDomesticTaxExpenseBenefit | (6.3)gmt_CurrentDomesticTaxExpenseBenefit
Foreign | 13.0 us-gaap_CurrentForeignTaxExpenseBenefit | 10.5 us-gaap_CurrentForeignTaxExpenseBenefit | 8.0 us-gaap_CurrentForeignTaxExpenseBenefit
Total current taxes | 14.3 us-gaap_CurrentIncomeTaxExpenseBenefit | 11.9 us-gaap_CurrentIncomeTaxExpenseBenefit | 1.7 us-gaap_CurrentIncomeTaxExpenseBenefit
Deferred |  |  |
Federal | 45.0 us-gaap_DeferredFederalIncomeTaxExpenseBenefit | 36.6 us-gaap_DeferredFederalIncomeTaxExpenseBenefit | 16.0 us-gaap_DeferredFederalIncomeTaxExpenseBenefit
State and local | 5.6 us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit | 5.3 us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit | (3.1)us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit
Deferred domestic taxes | 50.6 gmt_DeferredDomesticIncomeTaxExpenseBenefit | 41.9 gmt_DeferredDomesticIncomeTaxExpenseBenefit | 12.9 gmt_DeferredDomesticIncomeTaxExpenseBenefit
Foreign | 10.8 us-gaap_DeferredForeignIncomeTaxExpenseBenefit | 11.7 us-gaap_DeferredForeignIncomeTaxExpenseBenefit | 11.5 us-gaap_DeferredForeignIncomeTaxExpenseBenefit
Total deferred taxes | $ 61.4 us-gaap_DeferredIncomeTaxExpenseBenefit | $ 53.6 us-gaap_DeferredIncomeTaxExpenseBenefit | $ 24.4 us-gaap_DeferredIncomeTaxExpenseBenefit

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