Equity-Based Compensation (Performance Stock Units - Settled in Cash) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accrued equity based compensation		$ 26.1	$ 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		$ 21.5	$ 23.6
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSUs compensation expense	$ 8.9