Derivative Instruments and Hedging Activities - Gain or Loss Recognized on Foreign Currency Forward Contracts (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in Income on Derivative			$ (88,000)	$ (167,000)
Other Gain (Loss), Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in Income on Derivative			(88,000)	(167,000)
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contracts [Member] | Other Gain (Loss), Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in Income on Derivative	$ (564,000)	$ 54,000	$ (88,000)	$ (167,000)