New Accounting Pronouncements - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		7 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest expense, net	$ 134.9	$ 136.0		$ 404.8	$ 375.4
Accounting Standards Update 2017-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest expense, net	$ (15.9)		$ (39.4)