Notional Amounts of Derivative Financial Instruments and Related Fair Values Measured on Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	$ 191.3	$ 338.0
Total derivative financial instruments, fair value (net)	(6.1)	(6.4)
Designated as Hedging Instrument | Interest rate swap contract
Derivatives, Fair Value [Line Items]
Notional Amounts of Derivative Instruments, Liability	183.4	186.3
Designated as Hedging Instrument | Interest rate swap contract | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Fair value of Derivative Instruments, Liability	(6.5)	(4.6)
Not Designated as Hedging Instrument | Interest rate swap contract
Derivatives, Fair Value [Line Items]
Notional Amounts of Derivative Instruments, Liability	0	140.0
Not Designated as Hedging Instrument | Interest rate swap contract | Accrued expense
Derivatives, Fair Value [Line Items]
Fair value of Derivative Instruments, Liability	0	(0.8)
Not Designated as Hedging Instrument | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Notional Amounts of Derivative Instruments, Liability		11.7
Notional Amounts of Derivative Instruments, Asset	7.9
Not Designated as Hedging Instrument | Foreign exchange contracts | Accrued expense
Derivatives, Fair Value [Line Items]
Fair value of Derivative Instruments, Liability		(1.0)
Not Designated as Hedging Instrument | Foreign exchange contracts | Prepaid expenses and other [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 0.4