Summary of Forward Contracts Outstanding (Detail) (Fair Value, Inputs, Level 2, Foreign currency forward contracts, USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Fair Value, Inputs, Level 2 | Foreign currency forward contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax gain recognized in AOCI	$ 1,506	$ 4,024