Goodwill and Other Intangible Assets - Summary of Goodwill (Details) $ in Millions	9 Months Ended
Sep. 30, 2018 USD ($)
Goodwill [Roll Forward]
Balance as of December 31, 2017	$ 1,765.3
Acquisitions	26.9
Measurement period adjustments	12.7
Effect of movements in exchange rates and other	(33.9)
Balance as of September 30, 2018	1,771.0
Americas
Goodwill [Roll Forward]
Balance as of December 31, 2017	1,249.7
Acquisitions	0.0
Measurement period adjustments	12.7
Effect of movements in exchange rates and other	(4.9)
Balance as of September 30, 2018	1,257.5
EMEA
Goodwill [Roll Forward]
Balance as of December 31, 2017	249.0
Acquisitions	15.2
Measurement period adjustments	0.0
Effect of movements in exchange rates and other	(8.5)
Balance as of September 30, 2018	255.7
APAC
Goodwill [Roll Forward]
Balance as of December 31, 2017	266.6
Acquisitions	11.7
Measurement period adjustments	0.0
Effect of movements in exchange rates and other	(20.5)
Balance as of September 30, 2018	$ 257.8

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.

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