Investments (Available For Sale Investments) (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 25, 2011	Dec. 25, 2010
Net unrealized gains on the investments	$ 1,214,000	$ 760,000
Amortized Cost	71,366,000	76,907,000
Gross Unrealized Gains	1,222,000	942,000
Gross Unrealized Losses	8,000	182,000
Fair Market Value	72,580,000	77,667,000
Money Market Investments [Member]
Amortized Cost	1,536,000	535,000
Fair Market Value	1,536,000	535,000
Mortgage-Backed Securities [Member]
Amortized Cost	3,105,000	3,458,000
Gross Unrealized Gains	91,000	64,000
Gross Unrealized Losses		8,000
Fair Market Value	3,196,000	3,514,000
Corporate Bonds And Direct Obligations Of Government Agencies [Member]
Amortized Cost	53,717,000	60,330,000
Gross Unrealized Gains	1,107,000	872,000
Gross Unrealized Losses	8,000	151,000
Fair Market Value	54,816,000	61,051,000
U.S. Treasury Obligations [Member]
Amortized Cost	13,008,000	12,584,000
Gross Unrealized Gains	24,000	6,000
Gross Unrealized Losses		23,000
Fair Market Value	$ 13,032,000	$ 12,567,000