Sales, Gross Profit and Gross Profit Margin by Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Segment Reporting Information [Line Items]
Sales	$ 96,905	$ 79,769	$ 176,038	$ 154,840
Gross Profit	38,651	33,239	70,756	63,870
Gross profit margin percentage	39.90%	41.70%	40.20%	41.20%
Laser Products
Segment Reporting Information [Line Items]
Sales	43,828	40,433	85,688	78,597
Gross Profit	17,155	16,677	34,168	32,184
Gross profit margin percentage	39.10%	41.20%	39.90%	40.90%
Medical Technologies
Segment Reporting Information [Line Items]
Sales	34,791	22,135	57,158	45,692
Gross Profit	13,838	8,273	22,727	17,736
Gross profit margin percentage	39.80%	37.40%	39.80%	38.80%
Precision Motion
Segment Reporting Information [Line Items]
Sales	18,286	17,201	33,192	30,551
Gross Profit	7,949	8,290	14,365	14,058
Gross profit margin percentage	43.50%	48.20%	43.30%	46.00%
Corporate, Shared Services and Unallocated
Segment Reporting Information [Line Items]
Gross Profit	$ (291)	$ (1)	$ (504)	$ (108)