Business Segment, Geographic Area, Product and Significant Customer Information - Reconciliation of Segment Assets to Consolidated Total Assets (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Statement Of Financial Position [Abstract]
Total segment assets	$ 221,710	$ 216,699
Cash and cash equivalents and investments	608,499	627,399
Other current assets	38,593	36,242
Property, plant and equipment, net	79,709	80,516
Goodwill and intangible assets, net	164,090	162,294
Other assets	12,807	11,692
Total assets	$ 1,125,408	$ 1,134,842