Restructuring, Acquisition and Divestiture Related Costs - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Jul. 01, 2016	Jul. 03, 2015	Jul. 01, 2016	Jul. 03, 2015
Restructuring Cost And Reserve [Line Items]
Restructuring Costs		$ 1,972	$ 384	$ 4,684	$ 2,137
Proceeds from the sale of property, plant and equipment				3,631	116
Acquisition and related charges		1,733	(475)	1,979	(348)
Finders' Fees, Legal, Valuation And Other Professional Or Consulting Fees
Restructuring Cost And Reserve [Line Items]
Acquisition and related charges		1,700		2,000
Earn-out Agreement
Restructuring Cost And Reserve [Line Items]
Acquisition and related charges		1,400		$ 1,400
2016 Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring plan				During the third quarter of 2015, the Company initiated the 2016 restructuring program, which includes consolidating certain of our manufacturing operations to optimize our facility footprint and better utilize resources, costs associated with discontinuing our radiology product line and reducing redundant costs due to productivity cost savings and business volume reductions. We substantially completed the 2016 restructuring program during the second quarter of 2016. During the three and six months ended July 1, 2016, the Company incurred restructuring costs of $2.1 million and $4.6 million, respectively, related to the 2016 restructuring plan. As of July 1, 2016, the Company incurred cumulative costs related to this restructuring plan totaling $7.7 million. The Company expects to incur additional restructuring charges of $0.3 million to $0.5 million related to the 2016 restructuring plan.
Restructuring Costs		2,076		$ 4,576
2016 Restructuring | Laser Products
Restructuring Cost And Reserve [Line Items]
Restructuring Costs		299		768
2016 Restructuring | Vision Technologies
Restructuring Cost And Reserve [Line Items]
Restructuring Costs		1,719		3,458
2016 Restructuring | Precision Motion
Restructuring Cost And Reserve [Line Items]
Restructuring Costs		19		106
2016 Restructuring | Unallocated Corporate and Shared Services
Restructuring Cost And Reserve [Line Items]
Restructuring Costs		39		244
2016 Restructuring | Cumulative Restructuring Costs
Restructuring Cost And Reserve [Line Items]
Restructuring Costs				7,700
2016 Restructuring | Minimum
Restructuring Cost And Reserve [Line Items]
Additional restructuring costs				300
2016 Restructuring | Maximum
Restructuring Cost And Reserve [Line Items]
Additional restructuring costs				$ 500
2015 Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring plan				During the first quarter of 2015, the Company initiated a program to eliminate redundant costs, as a result of acquisition and divestiture activities, to better align our operations to our strategic growth plans, to further integrate our business lines, and as a consequence of our productivity initiatives. During the three and six months ended July 3, 2015, the Company incurred restructuring costs of $0.1 million and $1.5 million, respectively, in severance costs related to the 2015 restructuring plan. Restructuring costs incurred during the six months ended July 3, 2015 were $0.6 million, $0.5 million, $0.1 million and $0.3 million related to the Laser Products, Vision Technologies, Precision Motion, and Unallocated Corporate and Shared Services reportable segments, respectively.
Restructuring Costs			114		1,484
2015 Restructuring | Laser Products
Restructuring Cost And Reserve [Line Items]
Restructuring Costs					600
2015 Restructuring | Vision Technologies
Restructuring Cost And Reserve [Line Items]
Restructuring Costs					500
2015 Restructuring | Precision Motion
Restructuring Cost And Reserve [Line Items]
Restructuring Costs					100
2015 Restructuring | Unallocated Corporate and Shared Services
Restructuring Cost And Reserve [Line Items]
Restructuring Costs					300
2011 Restructuring
Restructuring Cost And Reserve [Line Items]
Restructuring plan				In November 2011, the Company announced a strategic initiative (“2011 restructuring”), which aimed to consolidate operations to reduce the Company’s cost structure and improve operational efficiency. As part of this initiative, the Company eliminated facilities through the consolidation of certain manufacturing, sales and distribution facilities and the exit of Semiconductor and Laser Systems businesses. The Company substantially completed the 2011 restructuring program by the end of 2013. In March 2016, the Company sold our previously exited Laser Systems facility located in Orlando, Florida for a net cash consideration of $3.6 million. Restructuring costs for the three and six months ended July 1, 2016 included facility costs related to the Orlando, Florida facility. These costs were recorded in the Unallocated Corporate and Shared Services reportable segment.
Restructuring Costs		$ (104)	$ 270	$ 108	$ 653
2011 Restructuring | Orlando Facility
Restructuring Cost And Reserve [Line Items]
Proceeds from the sale of property, plant and equipment	$ 3,600