Selected Quarterly Financial and Earnings Data (Unaudited) Quarterly Table (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 28, 2014	Sep. 28, 2014	Jun. 29, 2014	Mar. 30, 2014	Dec. 29, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Quarterly Financial Information Disclosure [Abstract]
Restaurant sales	$ 192,897	$ 179,822	$ 168,583	$ 151,453	$ 165,514	$ 168,312	$ 173,518	$ 156,139	$ 692,755	$ 663,483	$ 539,608
Operating income (loss) from continuing operations	(2,994)	330	1,597	(6,484)	972	209	(472)	(5,784)	(7,551)	(5,075)	(14,636)
Net income (loss)	$ (27,035)	$ (1,721)	$ (1,932)	$ (7,429)	$ (2,062)	$ (2,762)	$ (3,496)	$ (5,199)	$ (38,117)	$ (13,519)	$ (18,888)
Basic and diluted net loss per share	$ (0.78)	$ (0.05)	$ (0.06)	$ (0.32)	$ (0.09)	$ (0.12)	$ (0.15)	$ (0.23)