Net Investment Hedge Gains and Losses Recognized in AOCI (Detail) (Net Investment Hedges, USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative [Line Items]
Hedging Instrument Gain/(Loss) Recognized in AOCI (Before Tax)	$ 119.9	$ (88.8)	$ 79.7	$ (9.3)
Foreign Exchange Contracts
Derivative [Line Items]
Hedging Instrument Gain/(Loss) Recognized in AOCI (Before Tax)	106.2	(73.8)	74.3	(9.5)
Sterling Denominated Subordinated Debt
Derivative [Line Items]
Hedging Instrument Gain/(Loss) Recognized in AOCI (Before Tax)	$ 13.7	$ (15.0)	$ 5.4	$ 0.2