Sales, Gross Profit and Gross Profit Margin by Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 28, 2014	Mar. 29, 2013
Segment Reporting Information [Line Items]
Sales	$ 79,133	$ 75,071
Gross Profit	32,105	30,631
Gross profit margin percentage	40.60%	40.80%
Laser Products
Segment Reporting Information [Line Items]
Sales	41,860	38,164
Gross Profit	17,013	15,507
Gross profit margin percentage	40.60%	40.60%
Medical Technologies
Segment Reporting Information [Line Items]
Sales	22,367	23,557
Gross Profit	8,889	9,463
Gross profit margin percentage	39.70%	40.20%
Precision Motion
Segment Reporting Information [Line Items]
Sales	14,906	13,350
Gross Profit	6,416	5,768
Gross profit margin percentage	43.00%	43.20%
Corporate, Shared Services and Unallocated
Segment Reporting Information [Line Items]
Gross Profit	$ (213)	$ (107)