Net Investment Hedge Gains and Losses Recognized in AOCI (Detail) (Net Investment Hedges, USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative [Line Items]
Hedging Instrument Gain/(Loss) Recognized in AOCI (Before Tax)	$ (29.6)	$ (3.3)	$ (40.2)	$ 79.5
Foreign Exchange Contracts
Derivative [Line Items]
Hedging Instrument Gain/(Loss) Recognized in AOCI (Before Tax)	(22.9)	(2.0)	(31.9)	64.3
Sterling Denominated Subordinated Debt
Derivative [Line Items]
Hedging Instrument Gain/(Loss) Recognized in AOCI (Before Tax)	$ (6.7)	$ (1.3)	$ (8.3)	$ 15.2