Gains and Losses on Derivatives Designated as Hedging Instruments, Net Investment Hedging (Detail) (Net Investment Hedging [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	$ 18.9	$ (2.1)
Foreign Exchange Contract [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	11.3	(2.1)
long-term debt
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	$ 7.6	$ 0