Sales, Gross Profit and Gross Profit Margin by Reportable Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 03, 2015	Mar. 28, 2014
Segment Reporting Information [Line Items]
Sales	$ 94,614	$ 79,133
Gross Profit	40,006	32,105
Gross profit margin percentage	42.30%	40.60%
Laser Products
Segment Reporting Information [Line Items]
Sales	44,955	41,860
Gross Profit	19,375	17,013
Gross profit margin percentage	43.10%	40.60%
Medical Technologies
Segment Reporting Information [Line Items]
Sales	31,111	22,367
Gross Profit	12,513	8,889
Gross profit margin percentage	40.20%	39.70%
Precision Motion
Segment Reporting Information [Line Items]
Sales	18,548	14,906
Gross Profit	8,465	6,416
Gross profit margin percentage	45.60%	43.00%
Corporate, Shared Services and Unallocated
Segment Reporting Information [Line Items]
Gross Profit	$ (347)	$ (213)