Goodwill (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Goodwill, Gross		$ 1,246.7
Accumulated impairment		(485.5)
Goodwill	$ 878.0	761.2
Acquisitions	132.5
Currency translation	(15.7)
Americas [Member]
Goodwill [Roll Forward]
Goodwill, Gross		375.2
Accumulated impairment		0.0
Goodwill	482.9	375.2
Acquisitions	107.5
Currency translation	0.2
EMEIA [Member]
Goodwill [Roll Forward]
Goodwill, Gross		769.8
Accumulated impairment		(478.6)
Goodwill	290.8	291.2
Acquisitions	9.2
Currency translation	(9.6)
Asia Pacific [Member]
Goodwill [Roll Forward]
Goodwill, Gross		101.7
Accumulated impairment		(6.9)
Goodwill	104.3	$ 94.8
Acquisitions	15.8
Currency translation	$ (6.3)

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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- Definition

Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase (decrease) of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Topic 350
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-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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