Marketable Securities Auction Rate (Details) (USD $)	12 Months Ended				0 Months Ended		3 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011	Dec. 29, 2012 Total auction rate securities	May 22, 2012 Federally-insured or FFELP guaranteed student loan auction rate securities	Mar. 29, 2011 Federally-insured or FFELP guaranteed student loan auction rate securities	Apr. 02, 2011 Federally-insured or FFELP guaranteed student loan auction rate securities	Dec. 28, 2013 Federally-insured or FFELP guaranteed student loan auction rate securities	Dec. 29, 2012 Federally-insured or FFELP guaranteed student loan auction rate securities
Schedule of Available-for-sale Securities [Line Items]
Par Value					$ 2,600,000	$ 3,300,000		$ 5,700,000	$ 5,700,000
Fair value of marketable securities	106,746,000	69,582,000		4,717,000	2,300,000	2,800,000		5,241,000
Sale proceeds from student loan auction rate securities sold at par					2,600,000	3,300,000
Realized gain on sale of securities					400,000		600,000
Previously unrecognized gain relieved on sale of student loan auction rate securities	$ (337,000)	$ 78,000	$ 133,000		$ 100,000		$ 100,000