Summary of Significant Accounting Policies - Additional Information (Detail)				3 Months Ended	12 Months Ended
	Sep. 24, 2014 USD ($) Restaurants	Jul. 30, 2014 USD ($)	Jul. 11, 2014 Restaurant	Sep. 24, 2014 USD ($) Restaurants	Dec. 30, 2015 USD ($) Restaurants Supplier	Dec. 31, 2014 USD ($) Restaurants Supplier	Dec. 25, 2013 USD ($)	Mar. 11, 2016	Sep. 30, 2015 Restaurants	Jul. 01, 2015 Restaurants	Apr. 01, 2015 Restaurants	Jun. 25, 2014 Restaurants	Mar. 26, 2014 Restaurants	Dec. 26, 2012 USD ($)
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Total amount of outstanding debt					$ 123,600,000
Cash available					6,101,000	$ 11,499,000	$ 17,015,000							$ 21,487,000
Capitalized internal cost					1,100,000
Asset impairment charges					181,000	293,000	27,000
Amortization expense for deferred financing costs					304,000	1,302,000	2,007,000
Accrued insurance					5,021,000	3,818,000
Expense for payroll and benefits reserves					8,363,000	6,124,000	6,912,000
Promotional allowances amount					7,400,000	7,200,000	5,700,000
Initial franchise revenue					790,000	631,000	521,000
Advertising expense					13,900,000	13,500,000	11,900,000
Accrued advertising					204,000	832,000
Unrecognized tax benefits, accrual of interest or penalties					0	0
Unrecognized tax benefits, interest or penalties expenses					0	0
Percentage of cash savings in taxes realized as a result of utilizing net operating losses payable to pre-IPO stockholders		85.00%
Charge relating to present value of total expected TRA payments				$ 41,000,000	156,000	41,382,000
Write off of goodwill	$ 650,000				$ 0	650,000
Number of restaurants to develop and open under agreement | Restaurants	6			6
Initial Option [Member] | Trimaran Fund Management, LLC [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants to develop and open under agreement | Restaurant			15
Number of years available under plan			5 years
Additional Option [Member] | Trimaran Fund Management, LLC [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants to develop and open under agreement | Restaurant			100
Number of years available under plan			10 years
Franchise Development Agreement [Member] | Trimaran Fund Management, LLC [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Related party agreement, termination period			10 years
Related party agreement, termination description					The Franchise Development Option Agreement terminates (i) ten years after execution, or (ii) if the Initial Option is exercised, five years after that exercise.
Level 3 Measurements [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Write off of goodwill						700,000	600,000
Write off of underlying fixed assets						200,000
Area Development Fees [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Unrecognized area development fees					$ 856,000	486,000
Minimum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of monthly franchise fee					4.00%
Maximum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of monthly franchise fee					5.00%
Franchised Units [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Advertising revenue					$ 18,500,000	$ 17,600,000	15,800,000
Number of restaurants to develop and open under agreement | Restaurants	239			239	247	243			245	244	243	233	233
Interest Expense [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Amortization expense for deferred financing costs					$ 300,000	$ 1,300,000	2,000,000
General and Administrative Expense [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Preopening costs					1,500,000	1,200,000	200,000
Other Assets [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Deferred financing fees net of accumulated amortization					1,200,000	1,500,000
Additional [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Accrued advertising					79,000
Other Current Liabilities [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Charge relating to present value of total expected TRA payments					7,600,000
Other Noncurrent Liabilities [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Charge relating to present value of total expected TRA payments					33,900,000
Indefinite-lived Intangible Assets [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Asset impairment charges					$ 0	$ 0	$ 0
Supplier Concentration Risk [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of suppliers | Supplier					2	0
Supplier One [Member] | Accounts Payable [Member] | Supplier Concentration Risk [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration					12.00%
Supplier Two [Member] | Accounts Payable [Member] | Supplier Concentration Risk [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration					11.00%
Largest Supplier One [Member] | Purchased [Member] | Supplier Concentration Risk [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration					36.00%	36.00%	36.00%
The Greater Los Angeles Area [Member] | Franchised Units [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants to develop and open under agreement | Restaurants					138
The Greater Los Angeles Area [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration					79.00%	80.00%	80.00%
Parent [Member] | SubsequentEvent [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of new stores opened								1
Franchisee [Member] | SubsequentEvent [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of new stores opened								1
2013 First Lien Credit Agreement [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Write off of unamortized deferred finance costs					$ 8,100,000
2013 First Lien Credit Agreement [Member] | Maximum [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Dividends receivable from subsidiaries per fiscal year		$ 33,000,000
Total dividends receivable from subsidiaries		$ 11,000,000
2013 First Lien Credit Agreement [Member] | Senior Secured Revolving Credit Facility [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Amount of borrowings available					69,800,000		$ 7,700,000
2013 Credit Agreement [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Write off of unamortized deferred finance costs					$ 6,600,000