Fair Value Measurement (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Assets:
Marketable securities	$ 65,338	$ 68,464
Foreign exchange contracts	11
Total assets	65,349
Liabilities:
Foreign exchange contracts		16
Corporate bonds
Assets:
Marketable securities	65,338	68,464
Level I
Assets:
Foreign exchange contracts
Total assets
Liabilities:
Foreign exchange contracts
Level I | Corporate bonds
Assets:
Marketable securities
Level II
Assets:
Foreign exchange contracts	11
Total assets	65,349
Liabilities:
Foreign exchange contracts		16
Level II | Corporate bonds
Assets:
Marketable securities	65,338	68,464
Level III
Assets:
Foreign exchange contracts
Total assets
Liabilities:
Foreign exchange contracts
Level III | Corporate bonds
Assets:
Marketable securities