Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jul. 01, 2016	Jun. 30, 2017	Jul. 01, 2016
Schedule of Employee Service Share-based Compensation [Line Items]
Share-based Compensation	$ 868	$ 300	$ 1,378	$ 7,758
Employee stock options [Member]
Schedule of Employee Service Share-based Compensation [Line Items]
Share-based Compensation	493	153	761	5,049
Restricted stock [Member]
Schedule of Employee Service Share-based Compensation [Line Items]
Share-based Compensation	46	2	86	227
Restricted stock units [Member]
Schedule of Employee Service Share-based Compensation [Line Items]
Share-based Compensation	329	145	531	2,423
Nonemployee stock options [Member]
Schedule of Employee Service Share-based Compensation [Line Items]
Share-based Compensation	$ 0	$ 0	$ 0	$ 59