Assets and Liabilities Measured at Fair Value (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fair Value Assets
Total marketable securities	$ 58,414	$ 63,167
Foreign currency forward contracts
Fair Value Assets
Foreign currency forward contracts		628
Fair Value Liabilities
Foreign currency forward contracts		883
Money Market Funds
Fair Value Assets
Money market funds	5,633	458
Municipal bonds
Fair Value Assets
Total marketable securities	32,219	36,607
Corporate bonds
Fair Value Assets
Total marketable securities	26,195	26,560
Level 1 | Money Market Funds
Fair Value Assets
Money market funds	5,633	458
Level 2
Fair Value Assets
Total marketable securities	58,414	63,167
Level 2 | Foreign currency forward contracts
Fair Value Assets
Foreign currency forward contracts		628
Fair Value Liabilities
Foreign currency forward contracts		883
Level 2 | Municipal bonds
Fair Value Assets
Total marketable securities	32,219	36,607
Level 2 | Corporate bonds
Fair Value Assets
Total marketable securities	$ 26,195	$ 26,560