QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 29, 2013
Sep. 29, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 30, 2012
Sep. 23, 2012
Jun. 24, 2012
Mar. 25, 2012
Dec. 25, 2011
Sep. 25, 2011
Jun. 26, 2011
Dec. 29, 2013
Dec. 30, 2012
Dec. 25, 2011
Selected Quarterly Financial Information [Abstract]                            
Revenue $ 107,366 $ 96,919 $ 99,778 $ 93,204 $ 122,158 $ 96,219 $ 94,068 $ 80,673       $ 397,267 $ 393,118 $ 351,452
Gross profit 51,541 40,277 45,411 40,801 65,377 43,906 45,573 33,013       178,030 187,869  
Net earnings 11,260 4,546 6,602 3,793 15,097 7,698 7,611 2,919       26,201 33,325 22,186
Earnings per share                            
Basic - class A and B common stock (in dollars per share) $ 0.22 $ 0.09 $ 0.13 $ 0.08 $ 0.30 $ 0.14 $ 0.13 $ 0.05       $ 0.52 $ 0.61  
Diluted - class A and B common stock (in dollars per share) $ 0.22 $ 0.09 $ 0.13 $ 0.08 $ 0.30 $ 0.14 $ 0.13 $ 0.05       $ 0.52 $ 0.61 $ 0.37
Basic and diluted - class C common stock (in dollars per share)         $ 0 $ 0.15 $ 0.28 $ 0.19         $ 0.74  
Pre-tax charge for separation benefits 35 80 716 32 29 553 1,035 38            
Pre-tax long-lived asset impairment charge           493                
Broadcast license impairment         1,616       735     0 1,616 735
Pre-tax gain on the sale         $ (319)         $ 253 $ 245