Derivatives and Hedge Accounting - Summary of Fair Value of Foreign Currency Exchange Contracts (Detail) - Foreign exchange contracts - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Derivative designated as hedging instruments | Other current assets
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, asset	$ 10,892	$ 3,211
Derivative designated as hedging instruments | Other assets
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, asset	7,360	2,994
Derivative designated as hedging instruments | Accrued expense and other current liabilities
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, liability	481	1,430
Derivative designated as hedging instruments | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, liability	322	828
Derivative not designated as hedging instruments | Other current assets
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, asset	46	113
Derivative not designated as hedging instruments | Accrued expense and other current liabilities
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, liability	$ 74	$ 0