Other Comprehensive Income (Loss) - Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Amortization of prior service and net actuarial loss \| Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Amortization of prior service and net actuarial loss	$ 509	$ 429	$ 1,013	$ 774

Amount of revenue and income classified as other.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.4)
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Name:	us-gaap_OtherIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration