Fair Value of Financial Instruments - Gains and Losses on Derivative Instruments in Consolidated Statement of 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
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivatives (Effective Portion)	$ 3,210		$ 5,242
Derivatives Designated as Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivatives (Effective Portion)	3,210	3,359	5,242	1,407
Amount of Gain (Loss) Reclassified from Cumulative Other Comprehensive Loss into Income (Effective Portion)	944	(2,030)	449	1,512
Amount of Gain (Loss) Recognized in Income on Derivatives (Ineffective Portion)	(266)	(266)	(210)	(14)
Not Designated as Hedging Instruments [Member] | Location of Gain (Loss) Recognized in Income on Derivatives [Member] | Foreign Exchange Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	$ (130)	$ (436)	$ (633)	$ 30