Purchased Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Finite Lived Intangible Assets [Line Items]
Gross Assets	$ 51,731		$ 46,379
Accumulated Amortization	(32,965)		(32,166)
Net Assets	18,766	[1]	14,213	[2]
Technology and patents
Finite Lived Intangible Assets [Line Items]
Gross Assets	34,295		32,176
Accumulated Amortization	(23,405)		(22,869)
Net Assets	10,890		9,307
Customer relationships
Finite Lived Intangible Assets [Line Items]
Gross Assets	15,128		11,898
Accumulated Amortization	(8,392)		(8,148)
Net Assets	6,736		3,750
Leasehold interest
Finite Lived Intangible Assets [Line Items]
Gross Assets	1,358		1,355
Accumulated Amortization	(234)		(241)
Net Assets	1,124		1,114
Noncompete agreements
Finite Lived Intangible Assets [Line Items]
Gross Assets	950		950
Accumulated Amortization	(934)		(908)
Net Assets	$ 16		$ 42

[1] Restated and Revised, see Notes 2 and 7

[2] Revised, see Note 2