Retirement Plans and Postretirement Costs - Amounts Included in Accumulated Other Comprehensive Loss, Net of Tax (Details) $ in Thousands	Jun. 27, 2021 USD ($)
SERP
Amounts Included in Accumulated Other Comprehensive Loss, Net of Tax
Net actuarial loss	$ 639
Postretirement
Amounts Included in Accumulated Other Comprehensive Loss, Net of Tax
Net actuarial loss	$ 1,473

Amount, after tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669686-108580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (j)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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