Derivative Financial Instruments - Additional Information (Detail) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2012 AUD	Dec. 31, 2012 BRL	Dec. 31, 2012 GBP (£)	Dec. 31, 2012 MXN
Derivative Instruments And Hedging Activities [Line Items]
Notional amount of foreign currency contracts settled	$ 305.6	$ 318.9	$ 332.5
FOREX contracts outstanding in the aggregate notional amount	144.2			12.2	72.9	42.2	16.9
Net unrealized gains (losses) associated with FOREX contracts to be reclassified to earnings	$ 3.6