Fair Value Measurements and Financial Instruments - Fair Value Hierarchy Level for Company's Liabilities Measured (Detail) - Level 2 [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Other Current Assets [Member]
Fair Value Of Assets And Liabilities Measured On Recurring Basis [Line Items]
Forward foreign exchange contract asset	$ 157	$ 277
Accrued Liabilities [Member]
Fair Value Of Assets And Liabilities Measured On Recurring Basis [Line Items]
Forward foreign exchange contract liability	$ (95)	$ (925)