Other Non-Operating Income and Expenses, Net (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 27, 2021	Mar. 28, 2020
Other Non-Operating Income and Expenses, Net [Abstract]
Post-retirement income	$ (2)	$ (3)
Interest income	0	(2)
Miscellaneous expense	1	1
Other expense (income), net	$ (1)	$ (4)

The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7)
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

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