Revenue - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 28, 2018	Jan. 01, 2018
Adoption of Topic 606
Revenue [Line Items]
Contract liabilities	$ 4.8	$ 5.4
Revenue recognized	$ 3.0
Warranties
Revenue [Line Items]
Standard product warranty description	The Company generally provides warranties for its products. The standard warranty period is typically 12 months to 24 months for the Photonics and Precision Motion segments and 12 months to 36 months for the Vision segment. The standard warranty period for product sales is accounted for under the provisions of ASC 450, “Contingencies,” as the Company has the ability to ascertain the likelihood of the liability and can reasonably estimate the amount of the liability.
Accounts Receivable
Revenue [Line Items]
Standard payment terms	30 days
Maximum
Revenue [Line Items]
Percentage of revenue for professional services	3.00%
Period when revenue for professional and engineering services requested under customer contract is recognized	1 month
Incremental Cost amortization expected period	1 year
Transfer of a promised good to a customer and the customer’s payment	1 year
Remaining performance obligation for contracts	1 year
Maximum | Photonics and Precision Motion | Warranties
Revenue [Line Items]
Standard warranty period on products	24 months
Maximum | Vision | Warranties
Revenue [Line Items]
Standard warranty period on products	36 months
Minimum | Photonics and Precision Motion | Warranties
Revenue [Line Items]
Standard warranty period on products	12 months
Minimum | Vision | Warranties
Revenue [Line Items]
Standard warranty period on products	12 months