Derivative Financial Instruments and Hedging Activities Schedule of Notional Amounts (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Foreign exchange contracts	$ 12,039.9	$ 10,735.4
Swaps
Derivative [Line Items]
Foreign exchange contracts	552.9	929.5
Futures, forwards and spot
Derivative [Line Items]
Foreign exchange contracts	3,886.7	3,249.9
Written options
Derivative [Line Items]
Foreign exchange contracts	4,179.7	3,688.8
Purchased options
Derivative [Line Items]
Foreign exchange contracts	$ 3,420.6	$ 2,867.2