Unaudited Condensed Consolidated Statement of Changes in Stockholders' Equity - 9 months ended Sep. 30, 2018 - Successor - USD ($) $ in Millions	Total	Series A Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Beginning Balance at Dec. 31, 2017	$ 3,655.8	$ 576.0	$ 1.0	$ 2,590.3	$ (175.9)	$ 613.6	$ 1.4	$ 49.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustments due to ASU 2014-09	(22.5)					(22.5)
Net income	403.2					394.3		8.9
Dividends declared	(44.6)			1.1		(45.7)
Foreign currency translation adjustment	(4.5)						(4.5)
Series A Convertible Preferred Stock conversions	0.0	(576.0)	0.4	678.1		(102.5)
Share-based compensation for equity-classified awards	25.6			25.6
Common stock repurchases	(699.6)				(699.6)
Repurchases of employee common stock relinquished for tax withholding	(14.5)				(14.5)
Distributions to noncontrolling interests	(10.3)							(10.3)
Ending Balance at Sep. 30, 2018	$ 3,288.6	$ 0.0	$ 1.4	$ 3,295.1	$ (890.0)	$ 837.2	$ (3.1)	$ 48.0