Purchased Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Finite Lived Intangible Assets [Line Items]
Gross Assets	$ 51,493	$ 51,884
Accumulated Amortization	(37,521)	(36,879)
Net Assets	13,972	15,005
Technology and Patents
Finite Lived Intangible Assets [Line Items]
Gross Assets	34,250	34,524
Accumulated Amortization	(26,337)	(25,931)
Net Assets	7,913	8,593
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Gross Assets	14,920	15,004
Accumulated Amortization	(9,967)	(9,732)
Net Assets	4,953	5,272
Leasehold Interest
Finite Lived Intangible Assets [Line Items]
Gross Assets	1,373	1,406
Accumulated Amortization	(267)	(266)
Net Assets	1,106	1,140
Noncompete Agreements
Finite Lived Intangible Assets [Line Items]
Gross Assets	950	950
Accumulated Amortization	$ (950)	$ (950)