Notional Amounts of Derivative Financial Instruments and Related Fair Values Measured on Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	$ 185.8	$ 191.7
Total derivative financial instruments, fair value (net)	(4.5)	(5.4)
Designated as Hedging Instrument | Interest rate swap contract
Derivatives, Fair Value [Line Items]
Notional Amounts of Derivative Instruments, Liability	177.8	180.6
Designated as Hedging Instrument | Interest rate swap contract | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Fair value of Derivative Instruments, Liability	(5.1)	(5.8)
Designated as Hedging Instrument | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Notional Amounts of Derivative Instruments, Asset	6.4	6.4
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	0.1
Not Designated as Hedging Instrument | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Notional Amounts of Derivative Instruments, Asset	1.6	4.7
Not Designated as Hedging Instrument | Foreign exchange contracts | Prepaid expenses and other [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 0.2	$ 0.3