Commitments and Contingencies (Details) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 25, 2019 USD ($) item	Jun. 25, 2019 USD ($) item	Dec. 25, 2018 USD ($) item
Commitments and Contingencies
Estimated cost to complete capital project commitments (in dollars) \| $	$ 197.2	$ 197.2	$ 168.3
Number of suppliers providing most of the company's beef \| item	3	3
Lease Agreements
Commitments and Contingencies
Number of leases guarantees entity contingently liable \| item		7	7
Lease Agreements \| Maximum
Commitments and Contingencies
Contingently liable amount \| $	$ 14.3	$ 14.3	$ 14.8

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14435-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14557-108349

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=118943654&loc=d3e12021-110248

Name:	us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant