Sales, Gross Profit and Gross Profit Margin by Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 27, 2013		Sep. 28, 2012		Sep. 27, 2013		Sep. 28, 2012
Segment Reporting Information [Line Items]
Sales	$ 85,484		$ 69,520		$ 253,905		$ 205,085
Gross profit	35,791		28,853		103,453		87,201
Gross profit margin percentage	41.90%		41.50%		40.70%		42.50%
Laser Products
Segment Reporting Information [Line Items]
Sales	50,340		48,369		142,519		138,828
Gross profit	20,882		19,245		56,857		56,683
Gross profit margin percentage	41.50%		39.80%		39.90%		40.80%
Precision Technologies
Segment Reporting Information [Line Items]
Sales	35,144		21,151		111,386		66,257
Gross profit	14,964		9,903		46,759		31,230
Gross profit margin percentage	42.60%		46.80%		42.00%		47.10%
Corporate
Segment Reporting Information [Line Items]
Gross profit	$ (55)	[1]	$ (295)	[1]	$ (163)	[1]	$ (712)	[1]

[1] Corporate costs primarily represent unallocated overhead.