Financial Instruments and Fair Value Measurements - Gains and Losses Recognized on Foreign Exchange Forward Contracts (Details) - Other income (expense), net - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Gains (losses) on foreign exchange forward contracts	$ (11.9)		$ (17.1)
Gains (losses) on foreign exchange forward contracts		$ (2.7)		$ (9.6)

Aggregate impact of foreign currency derivatives on earnings for the period. Includes impact of foreign currency cash flow hedge ineffectiveness and the ineffectiveness of fair value hedging derivatives and full change in fair value of the foreign currency derivatives not designated as hedging instruments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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