Derivative Financial Instruments (Notional and Fair Values of Non-Designated Risk Management Derivative Instruments) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Fair Value Asset	$ 3,487.8	$ 1,864.5
Fair Value Liability	4,119.2	2,261.8
Nondesignated
Derivative [Line Items]
Notional Value	556.2	397.4
Fair Value Asset	0.8	0.2
Fair Value Liability	30.3	14.6
Nondesignated | Foreign Exchange Contracts
Derivative [Line Items]
Notional Value	250.9	244.6
Fair Value Asset	0.8	0.2
Fair Value Liability	1.5	3.7
Nondesignated | Other Financial Derivatives
Derivative [Line Items]
Notional Value	305.3	152.8
Fair Value Asset	0.0	0.0
Fair Value Liability	$ 28.8	$ 10.9