Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value Measurements, Recurring Basis - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Foreign exchange forward contracts
Assets
Foreign exchange forward contracts	$ 813	$ 690
Liabilities
Foreign exchange forward contracts	96	661
Money market funds
Assets
Money market funds	35,120	35,020
Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign exchange forward contracts
Assets
Foreign exchange forward contracts	0	0
Liabilities
Foreign exchange forward contracts	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Assets
Money market funds	35,120	35,020
Significant Other Observable Inputs (Level 2) | Foreign exchange forward contracts
Assets
Foreign exchange forward contracts	813	690
Liabilities
Foreign exchange forward contracts	96	661
Significant Other Observable Inputs (Level 2) | Money market funds
Assets
Money market funds	0	0
Significant Unobservable Inputs (Level 3) | Foreign exchange forward contracts
Assets
Foreign exchange forward contracts	0	0
Liabilities
Foreign exchange forward contracts	0	0
Significant Unobservable Inputs (Level 3) | Money market funds
Assets
Money market funds	$ 0	$ 0