Acquisitions (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Total cash consideration paid for acquisitions, net of cash acquired	$ (27.3)	$ (56.9)
Payments of contingent consideration for acquisitions	(12.9)	$ (2.9)
7S Group GmbH
Business Acquisition [Line Items]
Payments of contingent consideration for acquisitions	$ (10.3)

The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration