Related Party Transactions (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020 USD ($) restaurant	Jun. 25, 2019 USD ($) restaurant	Jun. 30, 2020 USD ($) restaurant	Jun. 25, 2019 USD ($) restaurant
Related Party Transactions
Number of restaurants	521		521
Franchise
Related Party Transactions
Number of restaurants	96	93	96	93
Officers, directors and shareholders \| Majority-owned
Related Party Transactions
Number of restaurants	1	1	1	1
Officers, directors and shareholders \| Franchise
Related Party Transactions
Number of restaurants	6	6	6	6
Fees received from franchise and license restaurants \| $	$ 0.2	$ 0.3	$ 0.5	$ 0.7
Number of restaurants for which the entity is contingently liable on the lease			1

Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07.1(c))
-URI http://asc.fasb.org/extlink&oid=116637345&loc=SL114874292-224272

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(e))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

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