Allocation of Acquisition Costs to Assets Acquired and Liabilities Assumed (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2012 Erc	Apr. 30, 2012 Erc	Sep. 30, 2012 Precision Photonics Corporation	Apr. 11, 2012 Precision Photonics Corporation	Sep. 30, 2012 Matcon Group Limited	Jul. 20, 2012 Matcon Group Limited
Schedule of Business Acquisitions, Cost of Acquired Entity [Line Items]
Accounts receivable	$ 14,520	$ 5,766		$ 877		$ 7,877
Inventory	5,803	4,224		932		647
Other current assets, net of cash acquired	2,366	607		251		1,508
Property, plant and equipment	10,469	2,738		1,936		5,795
Goodwill	52,285	10,506	10,500	13,986	14,000	27,793	27,800
Intangible assets	24,827	5,642		5,104		14,081
Other assets	210	67		13		130
Total assets acquired	110,480	29,550		23,099		57,831
Total liabilities assumed	(30,701)	(15,939)		(2,509)		(12,253)
Net assets acquired	$ 79,779	$ 13,611		$ 20,590		$ 45,578