Quarterly Data (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 25, 2013		Sep. 25, 2013		Jun. 26, 2013		Mar. 27, 2013		Dec. 26, 2012		Sep. 26, 2012		Jun. 27, 2012		Mar. 28, 2012		Dec. 25, 2013	Dec. 26, 2012	Dec. 28, 2011
Quarterly Financial Information Disclosure [Abstract]
Company restaurant sales	$ 81,092		$ 83,371		$ 82,841		$ 81,030		$ 81,733		$ 86,575		$ 91,239		$ 94,163		$ 328,334	$ 353,710	$ 411,595
Franchise and licensing revenue	33,165		33,904		33,730		33,460		34,216		34,370		33,492		32,575		134,259	134,653	126,939
Total operating revenue	114,257		117,275		116,571		114,490		115,949		120,945		124,731		126,738		462,593	488,363	538,534
Total operating costs and expenses	106,326		103,750		103,957		101,039		104,162		109,255		105,732		112,825		415,072	431,974	487,560
Operating income	7,931		13,525		12,614		13,451		11,787		11,690		18,999		13,913		47,521	56,389	50,974
Net income	$ 4,262		$ 7,031		$ 6,198		$ 7,081		$ 6,480		$ 5,363		$ 4,601		$ 5,865		$ 24,572	$ 22,309	$ 112,287
Basic net income per share	$ 0.05	[1]	$ 0.08	[1]	$ 0.07	[1]	$ 0.08	[1]	$ 0.07	[2]	$ 0.06	[2]	$ 0.05	[2]	$ 0.06	[2]	$ 0.27	$ 0.23	$ 1.15
Diluted net income per share	$ 0.05	[1]	$ 0.08	[1]	$ 0.07	[1]	$ 0.07	[1]	$ 0.07	[2]	$ 0.06	[2]	$ 0.05	[2]	$ 0.06	[2]	$ 0.26	$ 0.23	$ 1.13

[1] Per share amounts do not necessarily sum to the total year amounts due to changes in shares outstanding and rounding

[2] Per share amounts do not necessarily sum to the total year amounts due to changes in shares outstanding and rounding.