Business Summary and Basis of Presentation - New Accounting Pronouncements (Details) - USD ($) $ in Thousands	Oct. 01, 2019	Jul. 02, 2019	Jan. 02, 2019	Jan. 01, 2019	Oct. 02, 2018	Jul. 03, 2018	Jan. 02, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and cash equivalents	$ 3,086		$ 4,655	$ 4,655	$ 1,918		$ 3,361
Accounts receivable	2,279		2,616	2,391
Inventories	9,875		9,646	9,646
Prepaid expenses and other assets	4,291		3,231	6,474
Income tax receivable	191		185	185
Total current assets	19,722		20,333	23,351
Property and equipment, net	134,682		139,618	138,774
Operating lease assets, net	212,760		219,883	0
Goodwill	7,154		6,400	6,400
Goodwill	963		1,224	1,291
Other assets, net	2,346		2,216	2,216
Total long-term assets	357,905		369,341	148,681
Total assets	377,627		389,674	172,032
Accounts payable	8,145		7,854	7,854
Accrued payroll and benefits	9,725		13,391	13,391
Accrued expenses and other current liabilities	9,563		10,630	11,183
Current operating lease liabilities	22,431		0	0
Current portion of long-term debt	1,125		719	719
Total current liabilities	50,989		32,594	33,147
Long-term debt, net	41,963		44,183	44,183
Long-term operating lease liabilities, net	229,157		260,931	0
Deferred rent	0		148	37,334
Deferred tax liabilities, net	197		133	133
Other long-term liabilities	4,275		4,996	4,554
Total liabilities	326,581		342,985	119,351
Preferred stock—$0.01 par value, 1,000,000 shares authorized and undesignated as of January 1, 2019; no shares issued or outstanding	0		0	0
Common stock—$0.01 par value, 180,000,000 shares authorized as of January 1, 2019; 46,353,309 issued and 43,929,438 outstanding as of January 1, 2019	465		464	464
Treasury stock, at cost, 2,423,871 shares as of January 1, 2019	(35,000)		(35,000)	(35,000)
Additional paid-in capital	199,878		198,352	198,352
Accumulated deficit	(114,297)		(117,127)	(111,135)
Total stockholders’ equity	51,046	$ 46,903	46,689	52,681	$ 51,975	$ 26,169	$ 35,861
Total liabilities and stockholders’ equity	$ 377,627		389,674	$ 172,032
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and cash equivalents			0
Accounts receivable			225
Inventories			0
Prepaid expenses and other assets			(3,243)
Income tax receivable			0
Total current assets			(3,018)
Property and equipment, net			844
Operating lease assets, net			219,883
Goodwill			0
Goodwill			(67)
Other assets, net			0
Total long-term assets			220,660
Total assets			217,642
Accounts payable			0
Accrued payroll and benefits			0
Accrued expenses and other current liabilities			(553)
Current operating lease liabilities			0
Current portion of long-term debt			0
Total current liabilities			(553)
Long-term debt, net			0
Long-term operating lease liabilities, net			260,931
Deferred rent			(37,186)
Deferred tax liabilities, net			0
Other long-term liabilities			442
Total liabilities			223,634
Preferred stock—$0.01 par value, 1,000,000 shares authorized and undesignated as of January 1, 2019; no shares issued or outstanding			0
Common stock—$0.01 par value, 180,000,000 shares authorized as of January 1, 2019; 46,353,309 issued and 43,929,438 outstanding as of January 1, 2019			0
Treasury stock, at cost, 2,423,871 shares as of January 1, 2019			0
Additional paid-in capital			0
Accumulated deficit			(5,992)
Total stockholders’ equity			(5,992)
Total liabilities and stockholders’ equity			$ 217,642