Current Liabilities - Other Current Liabilities (Details) - USD ($) $ in Thousands	Oct. 01, 2016	Dec. 31, 2015		Oct. 03, 2015	Dec. 31, 2014	Jun. 28, 2014	Mar. 29, 2014
Accounts Payable and Accrued Liabilities, Current [Abstract]
Salaries and benefits	$ 11,030	$ 6,417
Warranty accrual	1,808	1,586		$ 1,775	$ 1,501	$ 1,597	$ 1,766
Advanced billings	581	543
Capital lease, current portion	716	831
Other	2,889	2,769
Balance, end of the period	$ 17,024	$ 12,146	[1]

[1] The balance sheet as of December 31, 2015 has been derived from the audited financial statements at that date.