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.