Commitments And Contingencies (Details) - USD ($) $ in Millions	Jun. 13, 2017	Dec. 27, 2016
Letters Of Credit
Commitments And Contingencies [Line Items]
Outstanding letters of credit	$ 1.2	$ 1.2

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant