Sales and Gross Margin by Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 27, 2013	Jun. 28, 2013	Mar. 29, 2013	Dec. 31, 2012	Sep. 28, 2012	Jun. 29, 2012	Mar. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Sales	$ 87,707	$ 85,484	$ 85,307	$ 83,114	$ 66,413	$ 69,520	$ 70,379	$ 65,186	$ 341,612	$ 271,498	$ 304,296
Gross profit	35,996	35,791	34,499	33,163	27,275	28,853	30,667	27,681	139,449	114,476	133,100
Laser Products
Segment Reporting Information [Line Items]
Sales									191,300	186,341	196,014
Gross profit									76,040	75,456	85,891
Medical Technologies
Segment Reporting Information [Line Items]
Sales									90,276	25,915	27,285
Gross profit									35,824	13,149	13,647
Precision Motion
Segment Reporting Information [Line Items]
Sales									60,036	59,242	80,997
Gross profit									27,779	26,796	35,552
Corporate
Segment Reporting Information [Line Items]
Gross profit									$ (194)	$ (925)	$ (1,990)