Operating Income (Loss) from Continuing Operations by Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Oct. 02, 2015	Jul. 03, 2015	Apr. 03, 2015	Dec. 31, 2014	Sep. 26, 2014	Jun. 27, 2014	Mar. 28, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Income (Loss) from Continuing Operations
Operating Income (Loss) from Continuing Operations	$ 4,214	$ 9,007	$ 10,315	$ 5,397	$ (34,176)	$ 6,822	$ 6,480	$ 4,068	$ 28,933	$ (16,806)	$ 19,446
Laser Products
Operating Income (Loss) from Continuing Operations
Operating Income (Loss) from Continuing Operations									35,971	33,053	25,143
Vision Technologies
Operating Income (Loss) from Continuing Operations
Operating Income (Loss) from Continuing Operations									(2,057)	(43,079)	3,566
Precision Motion
Operating Income (Loss) from Continuing Operations
Operating Income (Loss) from Continuing Operations									16,877	13,023	12,062
Unallocated Corporate and Shared Services
Operating Income (Loss) from Continuing Operations
Operating Income (Loss) from Continuing Operations									$ (21,858)	$ (19,803)	$ (21,325)