Impact of Derivative Financial Instruments on Consolidated Financial Statements (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pre-tax Gain (Loss) Recognized in Earnings	$ 1.3	$ (1.7)	$ (1.1)
Amount of Pre-tax (Loss) Recognized in OCI	(2.5)	(5.0)	(5.4)
Amount of Pre-tax Loss Reclassified from AOCI into Earnings	(1.4)	(5.0)	(17.3)
Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pre-tax Gain (Loss) Recognized in Earnings	0	0	0
Amount of Pre-tax (Loss) Recognized in OCI	0.1	0	0
Amount of Pre-tax Loss Reclassified from AOCI into Earnings	0	0	0
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	0
Amount of Pre-tax (Loss) Recognized in OCI	(2.6)	(5.0)	(5.4)
Amount of Pre-tax Loss Reclassified from AOCI into Earnings	(1.4)	(5.0)	0
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	0	(1.4)
Amount of Pre-tax (Loss) Recognized in OCI	0	0	0
Amount of Pre-tax Loss Reclassified from AOCI into Earnings	0	0	(17.3)
Not Designated as Hedging Instrument | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pre-tax Gain (Loss) Recognized in Earnings	1.3	(1.7)	0.3
Amount of Pre-tax (Loss) Recognized in OCI	0	0	0
Amount of Pre-tax Loss Reclassified from AOCI into Earnings	$ 0	$ 0	$ 0