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Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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Amount of liability recognized arising from contingent consideration in a business combination.

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Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled beyond one year or the normal operating cycle, if longer.

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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.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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The carrying amount of deferred costs.

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Amount of expense for Federal Deposit Insurance Corporation (FDIC) insurance.

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Remaining lease term of operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Represents the number of restaurants.

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The number of states the entity operates in as of the balance sheet date.

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DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 27, 2022 USD ($) restaurant segment state	Mar. 28, 2021	Dec. 26, 2021 USD ($)
Change in Accounting Estimate [Line Items]
Number of restaurants \| restaurant	158
Number of states \| state	13
Operating segments \| segment	1
Reportable segments \| segment	1
Number of restaurants opened \| restaurant	8
Contingent consideration liability	$ 20,243		$ 20,477
Accounts receivable	3,831		2,644
Federal deposit insurance corporation (up to)	300
Deferred costs	$ 1,400
Lessee operating lease term (in years)	12 months
Geographic \| Revenue \| New York City metropolitan area
Change in Accounting Estimate [Line Items]
Concentration risk (as a percent)	31.00%	32.00%
Credit card processors
Change in Accounting Estimate [Line Items]
Accounts receivable	$ 3,500		$ 1,100
Spyce
Change in Accounting Estimate [Line Items]
Contingent consideration liability	16,400
Contingent consideration liability	$ 20,200