Location and Amounts of Gains and Losses on Derivative Instruments Not Designated as Hedging Instruments (Detail) (Forward currency contracts, Other (income) expense, net, USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Forward currency contracts | Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) Recognized in Earnings	$ (5.1)	[1]	$ 3.0	[1]	$ (0.5)	[1]

[1] These derivative contracts mitigate changes in the value of remeasured foreign currency denominated intercompany loans attributable to changes in foreign currency exchange rates.