Summary of Reclassifications of Accumulated Other Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Other Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gain on marketable securities	$ 10,692	$ 6,667	$ 25,969	$ 8,497
Foreign exchange gain (loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gain (loss) on cash flow hedges	513	(10,581)	2,550	(16,588)
Cost Of Revenue
Accumulated Other Comprehensive Income (Loss) [Line Items]
Actuarial gain (loss) relating to defined benefit plan	$ 31	$ (7)	$ 5	$ 5