Organization and Summary of Significant Accounting Policies - Contract Estimates (Details) - USD ($) $ in Millions	Dec. 27, 2020	Dec. 29, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Provision for loss on contracts	$ 3.6	$ 3.1

Cumulative provision for contract losses not offset against related costs accumulated on the balance sheet.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 35
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=68068069&loc=d3e57777-111642

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