Income Taxes Tax Rate Reconciliation (Details)	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 29, 2019	Dec. 29, 2018	Dec. 29, 2018	Jun. 27, 2020	Jun. 29, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	35.00%	35.00%	21.00%	21.00%	28.10%
General Business Tax Credit				(1.80%)	(0.90%)	(0.80%)

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.Fact.4)
-URI http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

Name:	us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration