Segments - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) Segment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | Segment	2
Segment Reporting Information [Line Items]
Adjusted EBITDA from continuing operations	$ 833.3	$ 809.2	$ 850.1
Restatement Adjustment | Modified Calculation of Adjusted EBITDA to Exclude Interest Income
Segment Reporting Information [Line Items]
Adjusted EBITDA from continuing operations		$ 7.5	$ 6.8