Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)					3 Months Ended		12 Months Ended
	Apr. 01, 2021 USD ($) restaurant	Aug. 04, 2020 USD ($) item	Aug. 03, 2020 USD ($) item	Jul. 30, 2014	Mar. 31, 2021 USD ($) restaurant item segment	Mar. 25, 2020 USD ($) restaurant	Dec. 30, 2020 USD ($) item	Dec. 25, 2019 USD ($)
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | segment					1
Historical dine-in percentage					20.00%
Number of Restaurants Permanently Closed due to Covid-19 | restaurant					0
Leaves of absence and overtime pay due to COVID 19					$ 2,800,000
Total amount of outstanding debt					53,800,000
Cash available					6,669,000		$ 13,219,000
Amortization of deferred financing costs					62,000	$ 63,000
Accounts payable					9,622,000		7,472,000
Operating Lease ROU assets					176,838,000		177,129,000
Asset Impairment Charges					303,000	1,920,000
Unrecognized tax benefits, accrual of interest or penalties					0		0
Interest related to NOPA							100,000
Unrecognized tax benefits, interest or penalties expenses						0
Percentage of cash savings in taxes realized as a result of utilizing net operating losses payable to pre-IPO stockholders				85.00%
Tax Receivable Agreement (Income) Expenses					$ (77,000)	(120,000)
AMT Credits, CARES Act						400,000
Loyalty Rewards Program, Points Needed For One Reward | item		50	100
Loyalty Rewards Program, Award Earned		$ 5	$ 10
Loyalty Rewards Program, Expiration Period For Inactivity					1 year
Loyalty Reward Program, unused reward expiration period					6 months
Loyalty Rewards Program, Expected Loyalty Points Redemption Period					1 year
Accrued loyalty rewards program liability					$ 700,000		900,000
Stockholders' equity					$ 282,862,000	$ 248,605,000	$ 277,578,000	$ 245,566,000
Minimum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Temporary closure period					1 day
Maximum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Temporary closure period					3 days
Tax Receivable Agreement (Income) Expenses					$ (100,000)
Supplier Concentration Risk | Accounts Payable
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number Of Suppliers | item							2
Supplier Concentration Risk | Supplier One | Accounts Payable
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number Of Suppliers | item					1
Percentage of concentration					28.50%		24.20%
Supplier Concentration Risk | Supplier Two | Accounts Payable
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration							11.40%
Supplier Concentration Risk | Largest Supplier One | Purchased
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration					25.50%	27.40%
Geographic Concentration Risk | Revenue
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration					100.00%	100.00%
Subsequent Event
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Proceeds from Income Tax Refunds	$ 500,000
Texas
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants | restaurant					1	1
California
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants | restaurant					3	3
Greater Los Angeles area market | Geographic Concentration Risk | Revenue
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration					70.10%	72.40%
Closed Store
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Closed-store reserve expense					$ 300,000	$ 500,000
Company-operated
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants | restaurant					198
Number of Restaurants Temporary Closed | restaurant					45
Company-operated | Subsequent Event
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of Restaurants Temporary Closed | restaurant	2
Company-operated | Subsequent Event | Minimum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Temporary closure period	1 day
Company-operated | Subsequent Event | Maximum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Temporary closure period	3 days
Franchised
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants | restaurant					283
Number of Restaurants Temporary Closed | restaurant					15
Franchised | Subsequent Event
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of Restaurants Temporary Closed | restaurant	0