Financial Instruments and Fair Value Measurements - Gains and Losses Recognized on Foreign Exchange Forward Contracts (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other expense, net | Foreign Exchange Forward Contract
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Gains (losses) on foreign exchange forward contracts	$ 13.7	$ (11.9)	$ (10.9)	$ (17.1)