Fair Value of Derivative Instruments (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Net, Total	$ 22.8	[1]	$ 20.6	[1]
Derivative Liability, Fair Value, Net, Total	(16.8)	[1]	(3.5)	[1]
Foreign currency forward contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Net, Total			0.5	[1]
Derivative Liability, Fair Value, Net, Total			(0.5)	[1]
Foreign currency forward contracts [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Net, Total	22.8	[1]	18.0	[1]
Derivative Liability, Fair Value, Net, Total	(16.8)	[1]	(3.0)	[1]
Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Net, Total			$ 2.1	[1]

[1] Asset derivatives are included in other assets and liability derivatives are included in other liabilities.