Fair Value Measurement (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets:
Marketable securities	$ 58,930	$ 48,266
Foreign exchange contracts	48	9
Liabilities:
Foreign exchange contracts	12
Government bonds
Assets:
Marketable securities	500
Certificates of deposits
Assets:
Marketable securities	1	1
Corporate bonds
Assets:
Marketable securities	58,429	48,265
Level II
Assets:
Foreign exchange contracts	48	9
Liabilities:
Foreign exchange contracts	12
Level II | Government bonds
Assets:
Marketable securities	500
Level II | Certificates of deposits
Assets:
Marketable securities	1	1
Level II | Corporate bonds
Assets:
Marketable securities	$ 58,429	$ 48,265