Income Taxes (Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 02, 2018	Jan. 03, 2017	Dec. 29, 2015
Income Tax Disclosure [Abstract]
Federal income tax benefit at federal rate	$ (12,814)	$ (23,740)	$ (7,650)
State income tax benefit, net of federal tax	(1,790)	(2,975)	(960)
Other permanent differences	674	996	378
Foreign rate differential	(463)	(214)	(66)
Tax credits	(808)	(749)	(423)
Change in valuation allowance	(159)	27,353	0
Tax rate change	13,632	0	0
Deferred tax asset write-off	2,618	0	0
Other items, net	(1,097)	134	(145)
Total (benefit) provision for income taxes	$ (207)	$ 1,233	$ (8,734)
Effective income tax rate	0.50%	(1.80%)	38.80%