Acquisitions and Divestitures - 2014 Purchase Price Allocation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015
Assets acquired:
Goodwill	$ 653.3	$ 835.8	$ 675.8
2014 Acquisitions
Business Acquisition [Line Items]
Purchase price	295.8
Less: Cash acquired	20.2
Estimated purchase price, net of cash acquired	275.6
Less: Promissory notes issued	9.0
Less: Amounts due to sellers	3.4
Cash paid for acquisition of businesses	263.2
Assets acquired:
Cash and cash equivalents	20.2
Accounts receivable	257.9
Inventories	14.4
Property and equipment	55.9
Identifiable intangible assets	83.5
Goodwill	177.8
Other current and long-term assets	22.5
Liabilities assumed:
Accounts payable	(247.6)
Accrued expenses and other current liabilities	(50.7)
Non-current income tax liabilities and other long term liabilities	(18.7)
Initial noncontrolling interest upon acquisition of businesses	(19.4)
Estimated purchase price	$ 295.8