Derivative Financial Instruments (Net Investment Hedge Gains and Losses Recognized in AOCI) (Details) - Net Investment Hedges - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Derivative [Line Items]
Hedging Instrument Gain/(Loss) Recognized in AOCI (Before Tax)	$ 110.0	$ (81.1)	$ 83.5	$ 35.5
Foreign Exchange Contracts
Derivative [Line Items]
Hedging Instrument Gain/(Loss) Recognized in AOCI (Before Tax)	110.0	(81.1)	83.5	30.5
Sterling Denominated Subordinated Debt
Derivative [Line Items]
Hedging Instrument Gain/(Loss) Recognized in AOCI (Before Tax)	$ 0.0	$ 0.0	$ 0.0	$ 5.0