Impact of Derivative Financial Instruments on Condensed Consolidated Financial Statements (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pre-tax Gain (Loss) Recognized in Earnings	$ 1.0	$ 0.2
Amount of Pre-tax (Loss) Recognized in OCI	0.7	0.2
Amount of Pre-tax Loss Reclassified from AOCI into Earnings	0	(1.3)
Designated as Hedging Instrument | Interest rate swap contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pre-tax Gain (Loss) Recognized in Earnings	0	0
Amount of Pre-tax (Loss) Recognized in OCI	0.7	0.2
Amount of Pre-tax Loss Reclassified from AOCI into Earnings	0	(1.3)
Not Designated as Hedging Instrument | Interest rate swap contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pre-tax Gain (Loss) Recognized in Earnings	(0.1)	0
Amount of Pre-tax (Loss) Recognized in OCI	0	0
Amount of Pre-tax Loss Reclassified from AOCI into Earnings	0	0
Not Designated as Hedging Instrument | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pre-tax Gain (Loss) Recognized in Earnings	1.1	0.2
Amount of Pre-tax (Loss) Recognized in OCI	0	0
Amount of Pre-tax Loss Reclassified from AOCI into Earnings	$ 0	$ 0