Derivatives - Unrealized Gains/(Losses) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivatives
Gain/(Loss) recognized in OCI on Foreign currency derivatives	$ (15.1)	$ (3.9)	$ 12.2	$ 0.5
Gains/(losses) excluded from effectiveness testing recognized in other comprehensive income	$ (0.7)	$ 1.2	$ 2.8	$ 1.7