Summary of Refranchising and Franchise Acquisitions - Summary of Refranchising (Details) $ in Thousands	6 Months Ended
Jun. 18, 2019 USD ($) restaurant	Jun. 19, 2018 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Company-operated restaurants sold to franchisees \| restaurant	13
Proceeds from the sale of company-operated restaurants	$ 2,090	$ 0
Net assets sold (primarily furniture, fixtures and equipment)	(2,051)
Goodwill related to the company-operated restaurants sold to franchisees	(83)
Allocation to deferred franchise fees	(281)
Favorable sublease assets, net (b)	260
Loss on sale of company-operated restaurants	(65)
Favorable Lease Interests And Other Intangible Assets [Member] \| Stores Sold [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Finite-lived Intangible Assets Acquired	$ 700

Allocation to Deferred Franchise Fees

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- Definition

Retirement of the carrying amount of assets, primarily equipment, associated with all or a portion of company-operated restaurants sold during the period.

+ References

No definition available.

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The number of company-operated restaurants sold to franchisees during the period.

+ References

No definition available.

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The amount of net (unfavorable)/favorable lease assets/liabilities recorded during the period as a result of subleasing land, buildings and leasehold improvements to franchisees in connection with the sale of company-operated restaurants.

+ References

No definition available.

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Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2443-110228

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230

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Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

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- Definition

Amount of increase (decrease) of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

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