Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail)	2 Months Ended	3 Months Ended	4 Months Ended	6 Months Ended	12 Months Ended
	May 05, 2020	Mar. 24, 2020 USD ($)	Dec. 31, 2019 USD ($) $ / shares	Jun. 30, 2015 USD ($)	Dec. 28, 2021 USD ($) renewal Segment location vendor	Dec. 29, 2020 USD ($) location	Dec. 31, 2019 USD ($) location $ / shares shares	Dec. 28, 2021 USD ($)	Dec. 28, 2021 restaurants	Dec. 28, 2021 location	Dec. 28, 2021 $ / shares	Dec. 28, 2021 property	Dec. 29, 2020 restaurants	Dec. 29, 2020 location	Dec. 29, 2020 $ / shares
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Current Fiscal Year End Date					--12-28
Impairment of long-lived assets					$ 9,115,000	$ 8,287,000	$ 7,159,000
Document Period End Date					Dec. 28, 2021
DeferredGiftCardIncomeTotal						3,100,000		$ 3,300,000
Value per share as of June 30, 2015 | $ / shares			$ 3.59				$ 3.59				$ 3.65				$ 2.41
Sublease liabilities						1,464,000		1,635,000
Number of vendors | vendor					1
Noncurrent portion of advanced reimbursements						27,000		0
Current portion of advanced reimbursements						400,000		0
Depreciation and amortization expense					$ 23,300,000	23,200,000	$ 22,700,000
Property and equipment depreciation expense						103,885,000		124,798,000
Carrying value of capitalized software costs						2,500,000		4,300,000
Capitalized software costs					3,500,000	2,000,000	1,600,000
Capitalized software amortization expense					1,800,000	1,900,000	1,400,000
Interest capitalized in connection with construction					$ 21,000	$ 34,000	$ 100,000
Lease agreement term (in years)					50 years
Number of underperforming locations | location					5	8	7
Deductible per occurrence for general liability					$ 350,000
Percentage of net sales for advertising	2.50%				4.00%
Advertising expenses					$ 19,000,000	$ 18,800,000	$ 16,400,000
Pre-opening costs					$ 682,000	471,000	1,650,000
Number of operating segments | Segment					1
Number of reportable segments | Segment					1
Partnership monthly rental income				$ 1,400,000
Proceeds from credit facility					$ 40,000,000	66,000,000	41,000,000
Payments of Debt Issuance Costs					0	0	1,014,000
Reclassified financing costs						821,000		604,000
Number of Stores | property												62
Number of Restaurants, California | restaurants									368
Deferred gift card income						1,669,000		1,658,000
Goodwill, Impairment Loss		$ 87,300,000	$ 118,300,000		0	87,277,000	118,250,000
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)					$ 0	11,900,000	0
Trademarks
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Intangible assets written off		$ 11,900,000
Entity operated units
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants									294	294			295	295
Number of Restaurants, California | restaurants									231
Franchised units
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants									306	306			301	301
Number of Restaurants, California | restaurants									137
Minimum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of lease renewal options | renewal					1
Lease renewal term (in years)					5 years
Insurance coverage deductibles range for claims					$ 250,000
Maximum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of lease renewal options | renewal					4
Lease renewal term (in years)					10 years
Insurance coverage deductibles range for claims					$ 500,000
Buildings under capital leases
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Depreciation and amortization expense						500,000	500,000
Estimated useful lives of assets (in years)					20 years
assets held under finance leases [Domain]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Depreciation and amortization expense					$ 100,000	200,000
Property and equipment depreciation expense						300,000		$ 37,000
Construction-in-progress
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Capitalized construction costs					$ 1,400,000	800,000	1,800,000
Restaurant and other equipment | Minimum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of assets (in years)					3 years
Restaurant and other equipment | Maximum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of assets (in years)					15 years
Franchise revenue
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Revenue					$ (23,670,000)	(20,763,000)	(19,002,000)
Franchise advertising contributions
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Revenue					$ (17,647,000)	$ (15,116,000)	$ (14,516,000)
Warrants
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Shares/warrants repurchased (in shares/warrants) | shares							846,411
Average cost per share/warrant (in dollars per share/warrant) | $ / shares							$ 1.78