Depreciation and Amortization by Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2016	Apr. 03, 2015
Depreciation and Amortization
Depreciation and amortization	$ 5,831	$ 4,762
Laser Products
Depreciation and Amortization
Depreciation and amortization	1,544	1,582
Vision Technologies
Depreciation and Amortization
Depreciation and amortization	3,100	2,258
Precision Motion
Depreciation and Amortization
Depreciation and amortization	614	473
Unallocated Corporate and Shared Services
Depreciation and Amortization
Depreciation and amortization	$ 573	$ 449