Allocation of Acquisition Costs to Assets Acquired and Liabilities Assumed (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 ERC	Apr. 30, 2012 ERC	Dec. 31, 2012 Precision Photonics Corporation	Apr. 11, 2012 Precision Photonics Corporation	Dec. 31, 2012 Matcon Group Limited	Jul. 20, 2012 Matcon Group Limited	Dec. 31, 2011 Advanced Thin Films, LLC	Dec. 31, 2011 Microfluidics International Corporation	Dec. 31, 2011 Cvi Melles Griot
Business Acquisition [Line Items]
Accounts receivable	$ 14,411	$ 26,685		$ 5,766		$ 877		$ 7,768		$ 947	$ 1,760	$ 23,978
Current assets, net of cash acquired			24,679
Inventory	5,760	55,946		4,224		932		604		852	2,226	52,868
Other current assets, net of cash acquired	3,113	8,451		981		252		1,880		73	816	7,562
Property, plant and equipment	10,369	36,635	18,344	2,738		1,936		5,695		5,019	567	31,049
Goodwill	50,387	232,613	45,915	8,499	8,500	13,941	13,900	27,947	28,000	18,220	5,853	208,540
Intangible assets	24,827	136,929	29,861	5,642		5,104		14,081		11,435	9,717	115,777
Other assets	1,575	5,391	2,906	1,509		13		53		2,731	548	2,112
Total assets acquired	110,442	502,650	121,705	29,359		23,055		58,028		39,277	21,487	441,886
Total liabilities assumed	(30,754)	(56,289)	(30,439)	(16,074)	(4,700)	(2,465)		(12,215)		(4,766)	(2,951)	(48,572)
Net assets acquired	$ 79,688	$ 446,361	$ 91,266	$ 13,285		$ 20,590		$ 45,813		$ 34,511	$ 18,536	$ 393,314