Derivative Financial Instruments and Fair Value Measurements - Effect of Net Investment Hedges on AOCI (Details) - Euro-denominated notes - Net Investment Hedging - Designated as hedging instrument - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivative [Line Items]
Gain Recognized in Other Comprehensive Income	$ 22.4
(Loss) Recognized in Other Comprehensive Income		$ (21.2)