Commitments And Contingencies (Details) (USD $)	12 Months Ended					3 Months Ended
	Dec. 31, 2011	Dec. 25, 2010	Dec. 26, 2009	Dec. 31, 2011 Guarantee Payment Of Insurance Claims [Member]	Dec. 31, 2011 Credit Agreement [Member]	Mar. 31, 2007 Damage Award [Member]	Dec. 31, 2011 Damage Award [Member]	Dec. 29, 2007 Damage Award [Member]
Commitments and Contingencies [Line Items]
Letters of credit outstanding				$ 45,165,000	$ 33,499,000
Retained liability of self-insurance program								5,000,000
Operating Insurance and Claims Costs, Production	42,766,000	49,334,000	45,918,000			5,000,000
Self insurance reserve, current	76,624,000	40,215,000					40,200,000
Other receivables	$ 53,263,000	$ 23,943,000					$ 40,200,000