Commitments And Contingencies (Details) (USD $)	Jun. 25, 2011
Current Investments [Member]
Investments providing collateral for letters of credit to guarantee insurance claims	$ 30,489,000
Non-Current Investments [Member]
Investments providing collateral for letters of credit to guarantee insurance claims	19,694,000
Guarantee Payment Of Insurance Claims [Member]
Letters of credit outstanding	45,165,000
Under Credit Agreement [Member]
Letters of credit outstanding	$ 33,499,000