Fair Value Measurement (Detail) - USD ($) $ in Thousands |
Dec. 31, 2017 |
Dec. 31, 2016 |
---|---|---|
Assets: | ||
Marketable securities | $ 82,664 | $ 61,868 |
Foreign exchange contracts | 6 | |
Government bonds | ||
Assets: | ||
Marketable securities | 495 | 497 |
Certificates of deposits | ||
Assets: | ||
Marketable securities | 747 | |
Corporate bonds | ||
Assets: | ||
Marketable securities | 81,422 | 61,371 |
Level II | ||
Assets: | ||
Foreign exchange contracts | 6 | |
Level II | Government bonds | ||
Assets: | ||
Marketable securities | 495 | 497 |
Level II | Certificates of deposits | ||
Assets: | ||
Marketable securities | 747 | |
Level II | Corporate bonds | ||
Assets: | ||
Marketable securities | $ 81,422 | $ 61,371 |