Supplemental Disclosures to Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jul. 01, 2014
Supplemental Cash Flow Elements [Abstract]
Interest paid (net of amounts capitalized)	$ 571	$ 0
Income taxes paid	376	163
Changes in purchases of property and equipment accrued in accounts payable, net	$ 827	$ (204)