Description of the Business and Summary of Significant Accounting Policies - Aggregate Business Acquisitions Completed (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Cash paid, net of cash acquired	$ 52.1	$ 0.0
Excess purchase price allocated to Goodwill	2,930.7		$ 2,888.4
Earnings Based Metrics
Business Acquisition [Line Items]
Contingent consideration	$ 35.3
Minimum
Business Acquisition [Line Items]
Intangible assets acquired, discount rate	9.00%
Intangible assets acquired, royalty rate	1.00%
Maximum
Business Acquisition [Line Items]
Intangible assets acquired, discount rate	20.00%
Intangible assets acquired, royalty rate	16.00%
Aggregate total
Business Acquisition [Line Items]
Total Consideration	$ 57.8
Cash paid, net of cash acquired	52.1
Contingent consideration	4.9
Allocation of purchase price to Intangible assets, net	$ 46.0
Weighted average useful life of acquired intangible assets	9 years 2 months
Excess purchase price allocated to Goodwill	$ 14.6