Acquisitions - Allocation of Purchase Price (Details) - USD ($) $ in Millions	Dec. 31, 2016	Jul. 31, 2016	Jun. 30, 2016
Business Acquisition [Line Items]
Goodwill	$ 1,139.6		$ 999.3
NACC
Business Acquisition [Line Items]
Accounts receivable, net		$ 89.2
Other current assets		19.5
Property, plant and equipment		45.1
Intangible assets		204.1
Goodwill		140.4
Other non-current assets		1.6
Accounts payable		(14.4)
Accrued expenses and other current liabilities		(59.1)
Deferred taxes		(19.2)
Deferred revenue		(1.1)
Consideration paid, net of cash acquired		$ 406.2