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Equity-Based Compensation (Performance Stock Units - Settled in Cash) (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2019 | Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Accrued equity based compensation | $ 26.6 | $ 38.4
Performance stock units |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Percentage of target performance stock units earned | 200.00% |
Units converted (in shares) | 256,000 |
Closing period | 90 days |
Non Current Liabilities |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Accrued equity based compensation | $ 22.0 | $ 23.6
Performance stock units |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
PSUs compensation expense | $ 8.9 |

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