Supplemental Disclosures to Condensed Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended
	Oct. 03, 2017	Sep. 27, 2016
Class of Stock [Line Items]
Interest paid (net of amounts capitalized)	$ 3,028	$ 1,983
Income taxes refunded	(158)	(121)
Changes in purchases of property and equipment accrued in accounts payable, net	2,144	2,014
Common Stock | Common Class A
Class of Stock [Line Items]
Conversion of Series A convertible preferred stock to common stock	$ 18,500	$ 0