Effect of Derivative Instruments Designated as Hedges on AOCI (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Derivative Instruments, Gain (Loss)
Amount of (loss) gain reclassified from accumulated AOCI (effective portion)	$ (503)	$ 306	$ 206	$ (100)
Revenues | Foreign Exchange Contracts
Derivative Instruments, Gain (Loss)
Amount of (loss) gain reclassified from accumulated AOCI (effective portion)	(2)	(271)	(120)	(1,301)
Operating Expense | Foreign Exchange Contracts
Derivative Instruments, Gain (Loss)
Amount of (loss) gain reclassified from accumulated AOCI (effective portion)	$ 2	$ 628	$ 338	$ 1,128