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Commitments and Contingencies (Details) $ in Millions, $ in Millions | 3 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | ---
Jun. 30, 2019 USD ($) | Mar. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2018 CAD ($) | Sep. 30, 2018 USD ($) | Sep. 30, 2017 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($)
Loss Contingency, Damages Sought, Value |  |  |  | $ 10.0 |  |  |  |
Income Tax Examination, Estimate of Possible Loss |  |  | $ 37.4 |  |  |  |  |
Income Tax Examination, Penalties Accrued |  |  | $ 37.4 |  |  |  |  |
Income Tax Examination, Interest Expense | $ 0.5 | $ 0.5 |  |  |  |  |  |
Taxes Payable | 7.0 |  |  |  |  |  |  |
Income Tax Examination, Penalties and Interest Expense | $ 31.0 |  |  |  |  |  |  |
IRS-Walter Energy Claim 1 [Member] |  |  |  |  |  |  |  |
Loss Contingency, Estimate of Possible Loss |  |  |  |  |  |  |  | $ 554.3
IRS-Walter Energy Claim 1 Priority [Member] |  |  |  |  |  |  |  |
Loss Contingency, Estimate of Possible Loss |  |  |  |  |  |  | $ 229.1 |
IRS-Walter Energy Claim 2 [Member] |  |  |  |  |  |  |  |
Loss Contingency, Estimate of Possible Loss |  |  |  |  |  |  | 860.4 |
IRS-Walter Energy Claim 2 Priority [Member] |  |  |  |  |  |  |  |
Loss Contingency, Estimate of Possible Loss |  |  |  |  |  |  | $ 535.3 |
Product Concentration Risk [Member] |  |  |  |  |  |  |  |
Operating Leases |  |  |  |  |  |  |  |
Product Warranty Expense |  |  |  |  | $ 14.1 | $ 9.8 |  |

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