Derivatives and Hedge Accounting - Summary of Effect of Foreign Currency Exchange Contracts on Consolidated Statements of Income (Detail) - Foreign Currency Exchange Contracts [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivatives Designated as Hedging Instruments [Member] | Derivatives in Cash Flow Hedging Relationships [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	$ (1,474)	$ 2,542	$ 785	$ 9,552
Foreign Exchange Gain/(Loss) [Member] | Derivatives not Designated as Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivatives	(1,297)	732	799	3,451
Foreign Exchange Gain/(Loss) [Member] | Derivatives Designated as Hedging Instruments [Member] | Derivatives in Cash Flow Hedging Relationships [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Reclassified from AOCI into Income (Effective Portion)	(224)	(2,205)	(533)	(4,458)
Amount of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	$ 0	$ 0	$ 0	$ 0