Capital Additions (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Capital additions	$ 3,323	$ 3,280	$ 5,582
Operating Segments
Segment Reporting Information [Line Items]
Capital additions	2,751	2,795	4,865
Operating Segments | Equipment
Segment Reporting Information [Line Items]
Capital additions	1,857	1,260	2,717
Operating Segments | Photonics
Segment Reporting Information [Line Items]
Capital additions	894	1,535	2,148
Unallocated Amount to Segment
Segment Reporting Information [Line Items]
Capital additions	$ 572	$ 485	$ 717