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Income Taxes (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2018 | Mar. 31, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017
Income Tax Disclosure [Abstract] |  |  |  |  |  |
Tax expense (benefit) | $ 6.0 |  | $ 2.9 | $ 18.5 | $ 5.1 |
Effective tax rate | 9.90% |  | 7.10% | 16.20% | 5.10% |
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount |  |  | $ 3.5 |  | $ 3.5 |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |
Deferred tax liabilities, undistributed foreign earnings |  |  |  |  |  | $ 9.8
Tax Cuts and Jobs Act of 2017, incomplete Accounting, Change in tax rate, provisional income tax expense | $ 4.8 | $ 0.3 |  | $ 4.8 |  |
Accounting Standards Update 2016-09 [Member] |  |  |  |  |  |
Income Tax Disclosure [Abstract] |  |  |  |  |  |
Tax expense (benefit) | $ 3.4 |  | $ 9.6 | $ 5.5 | $ 25.5 |

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