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Share-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 23, 2020	Sep. 25, 2019	Sep. 23, 2020	Sep. 25, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation	$ 1,998	$ 2,176	$ 1,972	$ 7,142
Certain Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation	1,784	1,957	1,364	6,418
Board Members | Restricted stock units for board members
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation	$ 214	$ 219	$ 608	$ 724

X

- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

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-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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