Gains and Losses on Derivatives Designated as Hedging Instruments, Net Investment Hedging (Detail) - Net Investment Hedging [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	$ (1.3)	$ 12.1	$ 10.0	$ 8.4
Foreign Exchange Contract [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	(0.7)	$ 12.1	12.7	$ 8.4
Long Term Debt [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	$ (0.6)		$ (2.7)