Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Purchase commitments, net of advances	$ 9,500
Percentage of export-oriented units established	100.00%
Aggregate disputed amount amount related to transfer pricing and permanent establishment	$ 18,065	$ 17,963
Total bank guarantees and deposits in respect of contingencies	8,573	8,640
Amounts paid as deposits in respect of contingencies	6,499	6,690
Bank guarantee issued	$ 2,074	$ 1,950