Basis of Presentation and Summary of Significant Accounting Policies (Supplemental Cash Flow Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow Information
Interest paid, net of amounts capitalized	$ 77.1	$ 60.5	$ 57.8
Income taxes paid	9.2	12.5	6.5
Acquisitions of businesses (see Note 3):
Fair value of assets acquired, net of cash	97.2	124.9	0.0
Liabilities assumed	(31.5)	(89.8)	0.0
Goodwill	58.5	54.6	0.0
Noncontrolling interests	0.0	(18.3)	0.0
Equity incentive awards	(3.2)	0.0	0.0
Acquisition of businesses—net of cash acquired	121.0	71.4	0.0
Finance Leases
Supplemental Cash Flow Information
Non-cash finance lease additions	7.7	2.4	0.5
Operating Leases
Supplemental Cash Flow Information
Non-cash finance lease additions	$ 10.1	$ 0.0	$ 0.0