Entity Central Index Key Finite Lived Intangible Liabilities Gross Finite Lived Intangible Liabilities Accumulated Amortization Finite Lived Intangible Liabilities Amortization Expenses Next Twelve Months Finite Lived Intangible Liabilities Amortization Expenses Year Two Finite Lived Intangible Liabilities Amortization Expenses Year Three Finite Lived Intangible Liabilities Amortization Expenses Year Four Finite Lived Intangible Liabilities Amortization Expenses Year Five Finite Lived Intangible Liabilities Amortization Expenses After Year Five Document and entity information. Document And Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Well Known Seasoned Issuer Entity Current Reporting Status Entity Current Reporting Status Entity Voluntary Filers Entity Voluntary Filers Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Entity Public Float Entity Public Float Intangible liabilities noncurrent. Statement Of Financial Position [Abstract] Assets Assets [Abstract] Current assets: Assets Current [Abstract] Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Restricted cash Restricted Cash And Cash Equivalents At Carrying Value Accounts and other receivables, net Receivables Net Current Inventories Inventory Net Prepaid expenses and other current assets Prepaid Expense And Other Assets Current Deferred tax assets Deferred Tax Assets Net Current Total current assets Assets Current Property and equipment owned, net Property Plant And Equipment Net Property held under capital lease, net Capital Leases Balance Sheet Assets By Major Class Net Goodwill Goodwill Trademarks Indefinite Lived Trademarks Other intangible assets, net Other Intangible Assets Net Deferred tax assets Deferred Tax Assets Net Noncurrent Other assets Other Assets Noncurrent Total assets Assets Liabilities and Stockholders’ Equity Liabilities And Stockholders Equity [Abstract] Current liabilities: Liabilities Current [Abstract] Current portion of obligations under capital leases Capital Lease Obligations Current Accounts payable Accounts Payable Current Accrued salaries and vacation Employee Related Liabilities Current Accrued insurance Accrued Insurance Current Accrued income taxes payable Accrued Income Taxes Current Accrued interest Interest Payable Current Accrued advertising Accrued Advertising Current Other accrued expenses and current liabilities Other Liabilities Current Total current liabilities Liabilities Current Revolver loan Lines Of Credit Current Obligations under capital leases, net of current portion Capital Lease Obligations Noncurrent Deferred taxes, net of current portion Deferred Tax Liabilities Gross Noncurrent Other intangible liabilities, net Intangible Liabilities Noncurrent Other noncurrent liabilities Other Liabilities Noncurrent Total liabilities Liabilities Commitments and contingencies Commitments And Contingencies Stockholders’ Equity Stockholders Equity [Abstract] Preferred stock, $0.01 par value—100,000,000 shares authorized; none issued or outstanding Preferred Stock Value Common stock, $0.01 par value—200,000,000 shares authorized; 38,473,772 and 38,284,435 shares issued and outstanding Common Stock Value Additional paid-in capital Additional Paid In Capital Common Stock Accumulated deficit Retained Earnings Accumulated Deficit Total stockholders’ equity Stockholders Equity Total liabilities and stockholders’ equity Liabilities And Stockholders Equity Preferred stock, par value Preferred Stock Par Or Stated Value Per Share Preferred stock, shares authorized Preferred Stock Shares Authorized Preferred stock, shares issued Preferred Stock Shares Issued Preferred stock, shares outstanding Preferred Stock Shares Outstanding Common stock, par value Common Stock Par Or Stated Value Per Share Common stock, shares authorized Common Stock Shares Authorized Common stock, shares issued Common Stock Shares Issued Common stock, shares outstanding Common Stock Shares Outstanding Gain on business interruption insurance recovery lost profit. Generally recurring costs associated with normal operations including cost of services. Gain on business interruption insurance recovery property equipment and expenses. Expenses related to selling shareholders. Tax receivable agreement expenses. Income Statement [Abstract] Revenue Revenues [Abstract] Company-operated restaurant revenue Sales Revenue Services Net Franchise revenue Franchise Revenue Total revenue Revenues Cost of operations Cost Of Goods And Services Sold [Abstract] Food and paper costs Cost Of Services Direct Materials Labor and related expenses Cost Of Services Direct Labor Occupancy and other operating expenses Other Cost And Expense Operating Gain on recovery of insurance proceeds, lost profits Gain On Business Interruption Insurance Recovery Lost Profit Company restaurant expenses Company Restaurant Expenses General and administrative expenses General And Administrative Expense Franchise expenses Franchisor Costs Depreciation and amortization Depreciation And Amortization Loss on disposal of assets Gain Loss On Disposition Of Assets1 Expenses related to fire loss General Insurance Expense Gain on recovery of insurance proceeds, property, equipment and expenses Gain On Business Interruption Insurance Recovery Property Equipment And Expenses Asset impairment and closed-store reserves Restructuring Costs And Asset Impairment Charges Total expenses Costs And Expenses Gain on disposition of restaurants Gain Loss On Sale Of Business Income from operations Operating Income Loss Interest expense—net of interest income of $28, $49, and $63 for the years ended December 28, 2016, December 30, 2015, and December 31, 2014, respectively Interest Income Expense Net Early extinguishment of debt Gains Losses On Extinguishment Of Debt Expenses related to selling shareholders Expenses Related To Selling Shareholders Income tax receivable agreement expense Tax Receivable Agreement Expenses Income (loss) before (provision) benefit for income taxes Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest (Provision) benefit for income taxes Income Tax Expense Benefit Net income Net Income Loss Net income per share: Earnings Per Share [Abstract] Basic Earnings Per Share Basic Diluted Earnings Per Share Diluted Weighted average shares used in computing net income per share: Earnings Per Share Basic And Diluted Other Disclosures [Abstract] Basic Weighted Average Number Of Shares Outstanding Basic Diluted Weighted Average Number Of Diluted Shares Outstanding Investment income, bank earning allowance and miscellaneous interest. Interest income Investment Income Bank Earning Allowance And Miscellaneous Interest Statement Of Stockholders Equity [Abstract] Statement [Table] Statement [Table] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock [Member] Common Stock [Member] Additional Paid-in Capital [Member] Additional Paid In Capital [Member] Accumulated Deficit [Member] Retained Earnings [Member] Statement [Line Items] Statement [Line Items] Beginning balance, value Beginning balance, shares Shares Outstanding Stock based compensation Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value Issuance of common stock related to restricted shares, value Stock Issued During Period Value Restricted Stock Award Gross Issuance of common stock related to restricted shares, shares Stock Issued During Period Shares Restricted Stock Award Gross Issuance of common stock for initial public offering, net of offering costs of $10,914 Stock Issued During Period Value New Issues Issuance of common stock for initial public offering, net of offering costs of $10,914, shares Stock Issued During Period Shares New Issues Issuance of common stock upon exercise of stock options, value Stock Issued During Period Value Stock Options Exercised Issuance of common stock upon exercise of stock options, shares Stock Issued During Period Shares Stock Options Exercised Excess income tax benefit related to share-based compensation plans Adjustments To Additional Paid In Capital Tax Effect From Share Based Compensation Net income Ending balance, value Ending balance, shares Issuance of common stock for initial public offering, offering cost Expense Related To Distribution Or Servicing And Underwriting Fees Gain (loss) on business interruption insurance recovery. Payment related to tax receivable agreement. Fire insurance proceeds for property and equipment. Cashless exercise of stock options. Operating Cash Flows Direct Method [Abstract] Cash flows from operating activities Net Cash Provided By Used In Operating Activities Continuing Operations [Abstract] Adjustments to reconcile changes in net income to net cash provided by operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Depreciation and amortization Depreciation Depletion And Amortization Loss on early extinguishment of debt Stock-based compensation expense Share Based Compensation Interest accretion Accretion Expense Fire insurance proceeds for expenses paid and lost profit Proceeds From Insurance Settlement Operating Activities Gain on disposition of restaurants Gain on recovery of insurance proceeds, property, equipment and expenses Gain Loss On Business Interruption Insurance Recovery Impairment of property and equipment Asset Impairment Charges Closed-store reserves Restructuring Costs Amortization of deferred financing costs Amortization Of Financing Costs Amortization of favorable and unfavorable leases, net Amortization Of Above And Below Market Leases Excess income tax benefit related to share-based compensation plans Excess Tax Benefit From Share Based Compensation Operating Activities Deferred income taxes, net Deferred Income Tax Expense Benefit Payment related to tax receivable agreement Payment Related To Tax Receivable Agreement Changes in operating assets and liabilities: Increase Decrease In Operating Capital [Abstract] Accounts and other receivables, net Increase Decrease In Accounts And Other Receivables Inventories Increase Decrease In Inventories Prepaid expenses and other current assets Increase Decrease In Prepaid Deferred Expense And Other Assets Income taxes receivable/payable Increase Decrease In Income Taxes Other assets Increase Decrease In Other Operating Assets Accounts payable Increase Decrease In Accounts Payable Accrued salaries and vacation Increase Decrease In Employee Related Liabilities Accrued insurance Increase Decrease In Insurance Liabilities Other accrued expenses and liabilities Increase Decrease In Other Accrued Liabilities Net cash provided by operating activities Net Cash Provided By Used In Operating Activities Continuing Operations Cash flows from investing activities Net Cash Provided By Used In Investing Activities Continuing Operations [Abstract] Proceeds from disposition of restaurant Proceeds From Divestiture Of Businesses Proceeds from fire insurance for property and equipment Fire Insurance Proceeds For Property And Equipment Proceeds from disposition of assets Proceeds From Sales Of Assets Investing Activities Purchase of property and equipment Payments To Acquire Property Plant And Equipment Net cash flows used in investing activities Net Cash Provided By Used In Investing Activities Continuing Operations Cash flows from financing activities Net Cash Provided By Used In Financing Activities Continuing Operations [Abstract] Proceeds from borrowings on revolver and term loans Proceeds From Secured Lines Of Credit Payments on revolver loan Repayments Of Lines Of Credit Proceeds from issuance of common stock for initial public offering, net of expenses Proceeds From Issuance Of Common Stock Proceeds from issuance of common stock upon exercise of stock options, net of expenses Proceeds From Stock Options Exercised Payment of call premium on notes Payments Of Debt Extinguishment Costs Payment of obligations under capital leases Repayments Of Long Term Capital Lease Obligations Repayments on senior secured notes Repayments Of Notes Payable Deferred financing costs for Revolver Payments Of Financing Costs Excess income tax benefit related to share-based compensation plans Excess Tax Benefit From Share Based Compensation Financing Activities Amendment fee Payments For Fees Net cash flows used in financing activities Net Cash Provided By Used In Financing Activities Continuing Operations Decrease in cash and cash equivalents Cash And Cash Equivalents Period Increase Decrease Cash and cash equivalents, beginning of year Cash and cash equivalents, end of year Supplemental cash flow information Supplemental Cash Flow Elements [Abstract] Cash paid for interest, net of capitalized interest Interest Paid Cash paid during the year for income taxes, net Income Taxes Paid Net Noncash investing and financing activity Cash Flow Noncash Investing And Financing Activities Disclosure [Abstract] Unpaid purchases of property and equipment Capital Expenditures Incurred But Not Yet Paid Cashless stock option exercise Cashless Exercise Of Stock Options Accounting Policies [Abstract] Description of Business Nature Of Operations Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Property Plant And Equipment [Abstract] Property and Equipment Property Plant And Equipment Disclosure [Text Block] Goodwill And Intangible Assets Disclosure [Abstract] Goodwill and Other Intangible Assets and Liabilities Goodwill And Intangible Assets Disclosure [Text Block] Leases [Abstract] Leases Leases Of Lessee Disclosure [Text Block] Debt Disclosure [Abstract] Debt Instrument Debt Instrument [Axis] Debt Instrument, Name Debt Instrument Name [Domain] Prior credit agreement. Prior Credit Agreements [Member] Prior Credit Agreement [Member] Credit Agreements Debt Disclosure [Text Block] Other accrued expenses and current liabilities. Payables And Accruals [Abstract] Other Accrued Expenses and Current Liabilities Other Accrued Expenses And Current Liabilities [Text Block]