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Derivatives and Hedging Activities - Additional Information (Detail) - Derivatives designated as cash flow hedging instruments - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]          
Gain (loss) recognized in income, net $ (2,000) $ 69,000 $ 186,000 $ 191,000  
Foreign exchange forward and option contracts          
Derivative Instruments, Gain (Loss) [Line Items]          
Notional principal amount of Hedging Contracts $ 0   $ 0   $ 3,300,000