Business Acquisitions (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 991.0	$ 928.5	$ 874.7
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Tangible assets acquired, net of cash received	62.3
Intangible assets	92.6
Goodwill	70.0
Net deferred taxes	(8.2)
Liabilities assumed	(32.1)
TOTAL CONSIDERATION, NET OF CASH RECEIVED	$ 184.6