Fair Value Measurements (Details) $ in Millions	Dec. 31, 2019 USD ($) contract	Dec. 31, 2018 USD ($)
Cash Flow Hedging
Fair value of assets and liabilities measured on recurring basis
Number of forward contracts \| contract	2
Recurring basis
Fair value of assets and liabilities measured on recurring basis
Short-term investments	$ 17.4	$ 12.4
Forward contracts		2.4
Forward contracts	(1.3)
Contingent consideration	(75.0)
Total liability	(58.9)
Total asset		14.8
Recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair value of assets and liabilities measured on recurring basis
Short-term investments	17.4	12.4
Forward contracts		0.0
Forward contracts	0.0
Contingent consideration	0.0
Total asset	17.4	12.4
Recurring basis \| Significant Observable Inputs (Level 2)
Fair value of assets and liabilities measured on recurring basis
Short-term investments	0.0	0.0
Forward contracts		2.4
Forward contracts	(1.3)
Contingent consideration	0.0
Total liability	(1.3)
Total asset		2.4
Recurring basis \| Significant Unobservable Inputs (Level 3)
Fair value of assets and liabilities measured on recurring basis
Short-term investments	0.0	0.0
Forward contracts		0.0
Forward contracts	0.0
Contingent consideration	(75.0)
Total liability	$ (75.0)
Total asset		$ 0.0

Amount of liability recognized arising from contingent consideration in a business combination.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Section 35
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-SubTopic 30
-Section 25
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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