Derivative Financial Instruments (Cash Flow Hedge Derivative Gains and Losses Recognized in AOCI and Reclassified to Earnings) (Details) - Asset And Liability Management - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Foreign Exchange Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Net Gain/(Loss) Recognized in AOCI	$ 7.3	$ (2.0)	$ 16.2	$ 2.2
Net Gain/(Loss) Reclassified from AOCI to Net Income
Net Gain/(Loss) Reclassified from AOCI to Net Income	5.3	(0.8)	10.3	(2.4)
Interest Rate Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Net Gain/(Loss) Recognized in AOCI	1.6	2.7	1.3	7.8
Net Gain/(Loss) Reclassified from AOCI to Net Income
Net Gain/(Loss) Reclassified from AOCI to Net Income	0.1	0.8	0.2	1.8
Net Gain/(Loss) Reclassified from AOCI to Net Income | Foreign Exchange Contracts
Net Gain/(Loss) Reclassified from AOCI to Net Income
Other Operating Income	1.8	(0.6)	2.5	(1.8)
Interest Income	3.5	0.0	7.9	0.0
Other Operating Expense	0.0	(0.2)	(0.1)	(0.6)
Net Gain/(Loss) Reclassified from AOCI to Net Income | Interest Rate Contracts
Net Gain/(Loss) Reclassified from AOCI to Net Income
Other Operating Income	0.0	0.0	0.0	0.0
Interest Income	0.1	0.8	0.2	1.8
Other Operating Expense	$ 0.0	$ 0.0	$ 0.0	$ 0.0