Equity Method Investments And Cost Method Investments [Abstract] Equity method investments and cost method investments. Debt Instrument [Table] Schedule of Long-term Debt Instruments [Table] Short-term Debt, Type Short-term Debt, Type [Axis] Short-term Debt, Type Short-term Debt, Type [Domain] Letter of Credit Letter of Credit [Member] Swing Line Loans Swing Line Loans [Member] Swing line loans. Debt Instrument Debt Instrument [Axis] Debt Instrument, Name Debt Instrument, Name [Domain] 2014 Revolver Credit Agreement Two Thousand Fourteen [Member] Credit agreement two thousand fourteen. Variable Rate Variable Rate [Axis] Variable Rate Variable Rate [Domain] Federal Funds Rate Federal Funds Effective Swap Rate [Member] Base Rate Base Rate [Member] LIBOR London Interbank Offered Rate (LIBOR) [Member] Range Range [Axis] Range Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Credit Facility Credit Facility [Axis] Credit Facility Credit Facility [Domain] Senior Secured Revolving Credit Facility Revolving Credit Facility [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Senior secured revolving facility Line of Credit Facility, Maximum Borrowing Capacity Senior secured revolving facility term Debt Instrument, Term Sub limit of revolving facility Line of Credit Facility, Current Borrowing Capacity Letters of credit outstanding Letters of Credit Outstanding, Amount Revolver loan Long-term Line of Credit, Noncurrent Amount of borrowings available Line of Credit Facility, Remaining Borrowing Capacity Revolving credit facility maturity period Debt Instrument, Maturity Date Debt instrument basis percentage Debt Instrument, Basis Spread on Variable Rate Debt instrument, interest rate Line of Credit Facility, Interest Rate During Period Principal payments prior to maturity Debt Instrument, Periodic Payment, Principal Debt Instrument, Periodic Payment Debt Instrument, Periodic Payment Document And Entity Information [Abstract] 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 Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding (shares) Entity Common Stock, Shares Outstanding Payables and Accruals [Abstract] Other Accrued Expenses and Current Liabilities Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] Property, Plant and Equipment [Abstract] Property and Equipment Property, Plant and Equipment Disclosure [Text Block] Related Party Transactions [Abstract] Related Party Transactions Related Party Transactions Disclosure [Text Block] Debt Disclosure [Abstract] Credit Agreements Debt Disclosure [Text Block] Earnings Per Share [Abstract] Weighted-average shares outstanding—basic (shares) Weighted Average Number of Shares Outstanding, Basic Dilutive effect of stock options and restricted shares (shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted-average shares outstanding— diluted (shares) Weighted Average Number of Shares Outstanding, Diluted 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 cost 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 profit Gain On Business Interruption Insurance Recovery Lost Profit Gain on business interruption insurance recovery lost profit. Company restaurant expenses Company Restaurant Expenses Generally recurring costs associated with normal operations including cost of services. General and administrative expenses General and Administrative Expense Franchise expenses Franchisor Costs Depreciation and amortization Depreciation, Depletion and Amortization Loss on disposal of assets Gain (Loss) on Disposition of Assets Expenses related to fire loss General Insurance Expense Gain On Business Interruption Insurance Recovery Property Equipment And Expenses Gain On Business Interruption Insurance Recovery Property Equipment And Expenses Gain on business interruption insurance recovery property equipment and expenses. Recovery of securities lawsuits related legal expenses Recovery of securities class action legal expense Recovery of securities class action legal expense Asset impairment and closed-store reserves Restructuring Costs and Asset Impairment Charges Total expenses Costs and Expenses (Loss) gain on disposition of restaurants Gain (Loss) on Disposition of Business (Loss) income from operations Operating Income (Loss) Interest expense, net of interest income of $6 and $7 for the quarters ended September 27, 2017 and September 28, 2016, respectively and $17 and $22 for year-to-date ended September 27, 2017 and September 28, 2016, respectively. Interest Expense Income tax receivable agreement (income) expense Tax Receivable Agreement Expenses Tax receivable agreement expenses. (Loss) income before (benefit) provision for income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest (Benefit) provision for income taxes Income Tax Expense (Benefit) Net (loss) income Net Income (Loss) Attributable to Parent Net (loss) income per share Basic (usd per share) Earnings Per Share, Basic Diluted (usd per share) Earnings Per Share, Diluted Weighted-average shares used in computing net (loss) income per share Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract] Basic (shares) Diluted (shares) Schedule Of Property Plant And Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type Property, Plant and Equipment, Type [Domain] Land Land [Member] Buildings and improvements Building and Building Improvements [Member] Other property and equipment Property, Plant and Equipment, Other Types [Member] Construction in progress Construction in Progress [Member] Property Plant And Equipment [Line Items] Property, Plant and Equipment [Line Items] Property and equipment, gross Property, Plant and Equipment, Gross Less: accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property and equipment, net Property, Plant and Equipment, Net Depreciation Depreciation Gross value of assets under capital leases for buildings and improvements Capital Leased Assets, Gross Accumulated depreciation of assets under capital leases Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation Capital expenditures Payments to Acquire Productive Assets Capital expenditures for restaurant remodeling Payments for Capital Improvements Capital expenditures for new restaurants Payments to Acquire Other Property, Plant, and Equipment Impairment of property and equipment Impairment of Long-Lived Assets Held-for-use Accounting Policies [Abstract] Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] Schedule Of Related Party Transactions By Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party Related Party [Axis] Related Party Related Party [Domain] Trimaran Pollo Partners, LLC Trimaran Pollo Partners L L C [Member] Information pertaining to Trimaran Pollo Partners, LLC. Related Party Transaction [Line Items] Related Party Transaction [Line Items] Noncontrolling Interest, Description Noncontrolling Interest, Description Company's outstanding common stock owned by Trimaran Pollo Partners, L.L.C. Equity Method Investment, Ownership Percentage Outstanding membership interest, percentage Percentage Of Membership Interests Percentage of membership interests. Ownership percentage by stockholders Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Liquidity Liquidity Policy [Text Block] Liquidity Policy Text Block. Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Concentration of Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Goodwill and Indefinite Lived Intangible Assets Goodwill and Intangible Assets, Policy [Policy Text Block] Fair Value Measurement Fair Value Measurement, Policy [Policy Text Block] Impairment of Long-Lived Assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Costs Associated with Exit or Disposal Activities or Restructurings, Policy Costs Associated with Exit or Disposal Activities or Restructurings, Policy Number of Restaurants Number of Restaurants Income Taxes Income Tax, Policy [Policy Text Block] Other Liabilities Disclosure [Abstract] Accrued sales and property taxes Taxes Payable, Current Income tax receivable agreement payable Payable Under Tax Receivable Agreement Current Payable under tax receivable agreement current. Gift card liability Gift Card Liability, Current Other Other Accrued Liabilities, Current Total other accrued expenses and current liabilities Other Liabilities, Current Computation of Basic and Diluted Net Income per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Reconciliation of Basic and Diluted Share Counts Schedule of Weighted Average Number of Shares [Table Text Block] Schedule of Other Accrued Expenses and Current Liabilities Other Current Liabilities [Table Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stock-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Interest Income Investment Income, Bank Earning Allowance And Miscellaneous Interest Investment Income, Bank Earning Allowance And Miscellaneous Interest Statement of Financial Position [Abstract] Preferred stock, par value (usd per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized (shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (shares) Preferred Stock, Shares Issued Preferred stock, shares outstanding (shares) Preferred Stock, Shares Outstanding Common stock, par value (usd per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (shares) Common Stock, Shares Authorized Common stock, shares issued (shares) Common Stock, Shares, Issued Common stock, shares outstanding (shares) Common Stock, Shares, Outstanding Schedule of Other Noncurrent Liabilities Other Noncurrent Liabilities [Table Text Block] Schedule of Costs and Related Accumulated Depreciation and Amortization of Major Classes of Property Property, Plant and Equipment [Table Text Block] Statement of Cash Flows [Abstract] Statement [Table] Statement [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Statement [Line Items] Statement [Line Items] Interest Paid Interest Paid Net income Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Stock-based compensation expense Share-based Compensation Fire insurance proceeds for expenses paid and lost profit Proceeds from Insurance Settlement, Operating Activities Loss on disposal of assets Gain on recovery of insurance proceeds, property, equipment and expenses Gain Loss On Business Interruption Insurance Recovery Gain (loss) on business interruption insurance recovery. Gain on recovery of insurance proceeds, lost profits Closed-store reserve Restructuring Costs Amortization of deferred financing costs Amortization of Debt Issuance 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) Increase (Decrease) in Accounts and Other Receivables Increase (Decrease) in Accounts and Other Receivables Increase (Decrease) in Inventories Increase (Decrease) in Inventories Increase (Decrease) in Prepaid Expense and Other Assets Increase (Decrease) in Prepaid Expense and Other Assets Increase (Decrease) in Income Taxes Increase (Decrease) in Income Taxes Increase (Decrease) in Other Operating Assets Increase (Decrease) in Other Operating Assets Increase (Decrease) in Accounts Payable Increase (Decrease) in Accounts Payable Increase (Decrease) in Employee Related Liabilities Increase (Decrease) in Employee Related Liabilities Increase (Decrease) in Insurance Liabilities Increase (Decrease) in Insurance Liabilities Increase (Decrease) in Other Accrued Liabilities Increase (Decrease) in Other Accrued Liabilities Increase (Decrease) in Restricted Cash Increase (Decrease) in Restricted Cash Net cash flows provided by operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Proceeds from sale of restaurant Proceeds from Divestiture of Businesses Fire insurance proceeds for property and equipment Fire Insurance Proceeds For Property And Equipment Fire insurance proceeds for property and equipment. 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 Payments on revolver loan Repayments of Lines of Credit Proceeds from issuance of common stock upon exercise of stock options, net of expenses Proceeds from Issuance of Common Stock Payment of obligations under capital leases Repayments of Long-term Capital Lease Obligations Excess income tax benefit related to share-based compensation plans Excess Tax Benefit from Share-based Compensation, Financing Activities Net cash flows used in financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations Increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Income Taxes Paid Income Taxes Paid Capital Expenditures Incurred but Not yet Paid Capital Expenditures Incurred but Not yet Paid Commitments and Contingencies Disclosure [Abstract] Other Commitments [Table] Other Commitments [Table] Category of Item Purchased Category of Item Purchased [Axis] Long-term Purchase Commitment, Category of Item Purchased Long-term Purchase Commitment, Category of Item Purchased [Domain] Chicken Chicken [Member] Chicken. Guarantor Obligations, Nature Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature Guarantor Obligations, Nature [Domain] Property Lease Guarantee Property Lease Guarantee [Member] Title of Individual Title of Individual [Axis] Relationship to Entity Relationship to Entity [Domain] Officers Officer [Member] Other Commitments [Line Items] Other Commitments [Line Items] Date of class action filed in court Loss Contingency, Lawsuit Filing Date Number of lawsuits consolidated Number Of Lawsuits Number of lawsuits. Purchase commitments, estimated obligations Purchase Obligation Number of leases assigned to franchisees Number Of Leases Number of leases. Latest lease expiration year Lease Expiration Year Lease expiration year. Contingent lease obligations, maximum exposure Guarantor Obligations, Maximum Exposure, Undiscounted Contingent lease obligations, maximum exposure, if discounted at estimated pre-tax cost of debt Guarantee Obligations Maximum Net Exposure Guarantee obligations maximum net exposure. Number of at-will employment agreements Number Of Employment Agreements Number of employment agreements. Assets Assets [Abstract] Current assets: Assets, Current [Abstract] Restricted cash Restricted Cash and Cash Equivalents, Current Accounts and other receivables, net Receivables, Net, Current Inventories Inventory, Net Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Property and equipment owned, net Property held under capital leases, 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 Income Tax Assets, Net Other assets Other Assets, Noncurrent Total assets Assets Liabilities and Stockholders' Equity Liabilities and 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 Other accrued expenses and current liabilities Total current liabilities Liabilities, Current Obligations under capital leases, net of current portion Capital Lease Obligations, Noncurrent Deferred taxes Deferred Tax Liabilities, Gross, Noncurrent Other intangible liabilities, net Intangible Liabilities Noncurrent Intangible liabilities noncurrent. Other noncurrent liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies Commitments and Contingencies Stockholders' Equity Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, $0.01 par value, 100,000,000 shares authorized; none issued or outstanding Preferred Stock, Value, Issued Common stock, $0.01 par value—200,000,000 shares authorized; 38,652,918 and 38,473,772 shares issued and outstanding Common Stock, Value, Issued Additional paid-in-capital Additional Paid in Capital, Common Stock Accumulated deficit Retained Earnings (Accumulated Deficit) Total stockholders' equity Stockholders' Equity Attributable to Parent Total liabilities and stockholder’s equity Liabilities and Equity Other Liabilities, Noncurrent [Abstract] Deferred rent Deferred Rent Credit, Noncurrent Income tax receivable agreement payable Payable Under Tax Receivable Agreement Noncurrent Payable under tax receivable agreement noncurrent. Other Other Sundry Liabilities, Noncurrent Total other noncurrent liabilities Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Other Noncurrent Liabilities Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Noncurrent [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis Of Presentation And Summary Of Significant Accounting Policies [Table] Basis Of Presentation And Summary Of Significant Accounting Policies [Table] Basis of presentation and summary of significant accounting policies table. Scenario, Actual [Member] Scenario, Actual [Member] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Los Angeles [Member] Los Angeles [Member] Information pertaining to Los Angeles. Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Legal Entity [Axis] Legal Entity [Axis] Legal Entity Type of Counterparty [Domain] Legal Entity Type of Counterparty [Domain] Franchisees [Member] Franchisees [Member] Franchisees. Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Nonrecurring [Member] Fair Value, Measurements, Nonrecurring [Member] Related Party [Axis] Related Party [Domain] Trimaran Pollo Partners L L C [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2015-07 [Member] Accounting Standards Update 2015-07 [Member] Supplier [Axis] Supplier [Axis] Share-based Goods and Nonemployee Services Transaction, Supplier [Domain] Share-based Goods and Nonemployee Services Transaction, Supplier [Domain] Supplier Two Supplier Two [Member] Supplier two. Largest Supplier One Largest Supplier One [Member] Largest supplier one. Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Franchisor Disclosure Franchisor Disclosure [Axis] Franchisor Disclosure Franchisor Disclosure [Domain] Entity Operated Units Entity Operated Units [Member] Franchised Units Franchised Units [Member] Concentration Risk Benchmark Concentration Risk Benchmark [Axis] Concentration Risk Benchmark Concentration Risk Benchmark [Domain] Accounts Payable Accounts Payable [Member] Purchased Purchased [Member] Purchased. Revenue Sales Revenue, Net [Member] Concentration Risk Type Concentration Risk Type [Axis] Concentration Risk Type Concentration Risk Type [Domain] Supplier Concentration Risk Supplier Concentration Risk [Member] Geographic Concentration Risk Geographic Concentration Risk [Member] Asset Class Asset Class [Axis] Asset Class Asset Class [Domain] Indefinite-lived Intangible Assets Indefinite-lived Intangible Assets [Member] Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] Basis of presentation and summary of significant accounting policies. Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Number of operating segments Number of Operating Segments Restricted dividend payments, description Restriction to Transfer Funds Restrictive covenants, maximum annual repurchase or redemption of qualified entity interests Debt Instrument, Restrictive Covenants, Maximum Annual Repurchase or Redemption of Qualified Entity Interests Debt Instrument, Restrictive Covenants, Maximum Annual Repurchase or Redemption of Qualified Entity Interests Restrictive covenants, maximum annual payment for stock option plans, employment agreements and incentive plans Debt Instrument, Restrictive Covenants, Maximum Annual Payment For Stock Option Plans, Employment Agreements and Incentive Plans Debt Instrument, Restrictive Covenants, Maximum Annual Payment For Stock Option Plans, Employment Agreements and Incentive Plans Restrictive covenants, maximum annual payment for other restricted payments Debt Instrument, Restrictive Covenants, Maximum Annual Payment For Other Restricted Payments Debt Instrument, Restrictive Covenants, Maximum Annual Payment For Other Restricted Payments Maximum leverage ratio Debt Instrument, Covenant Description, Maximum Leverage Ratio Debt Instrument, Covenant Description, Maximum Leverage Ratio Covenant description, coverage ratio Debt Instrument, Covenant Description, Minimum Coverage Ratio Debt Instrument, Covenant Description, Minimum Coverage Ratio Total amount of outstanding debt Long-term Debt and Capital Lease Obligations Cash available Number of restaurants damaged Number Of Restaurants Damaged By Fire Number of restaurants damaged by fire. Expenses incurred from fire damage Expenses incurred from fire damage Expenses incurred from fire damage Property, Plant and Equipment, Disposals Disposal Group, Including Discontinued Operation, Assets Number of Restaurants Impaired Number of Restaurants Impaired Number of Restaurants Impaired Recovery of Securities Class Action Legal Costs Recovery of Securities Class Action Legal Costs Recovery of Securities Class Action Legal Costs Costs incurred directly related to fire (less than $0.1 million) Amount received from insurance company in cash Proceeds from Insurance Premiums Collected Operating lease obligations Operating Leases, Future Minimum Payments Due Number of suppliers Number Of Suppliers Number of suppliers. Percentage of concentration Concentration Risk, Percentage Asset impairment charges Asset Impairment Charges Unrecognized tax benefits, accrual of interest or penalties Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Unrecognized tax benefits, interest or penalties expenses Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense Percentage of cash savings in taxes realized as a result of utilizing net operating losses payable to pre-IPO stockholders Percentage Of Operating Loss Carryforwards Tax Savings Payable To Pre Initial Public Offering Stockholders Percentage of operating loss carry forwards tax savings payable to pre initial public offering stockholders. Recovery of securities class action legal expense Number of Restaurants Closed Number of Restaurants Closed Number of Restaurants Closed Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Fair Value Disclosures [Abstract] Fair Value Measurements, Nonrecurring [Table Text Block] Fair Value Measurements, Nonrecurring [Table Text Block] Fair Value, Option, Qualitative Disclosures Related to Election [Table] Fair Value, Option, Qualitative Disclosures Related to Election [Table] Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] Numerator: Net Income (Loss) Attributable to Parent [Abstract] Denominator: Weighted-average shares outstanding—diluted (shares) Net income per share—basic (usd per share) Net income per share—diluted (usd per share) Anti-dilutive securities not considered in diluted EPS calculation (shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type Award Type [Axis] Equity Award Equity Award [Domain] Premium Options Premium Options [Member] Premium options. Restricted Stock Restricted Stock [Member] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Common stock, options outstanding (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Common stock, options vested (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares Common stock, options unvested (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares Stock options exercised (shares) Number of options granted at fair market value (shares) Unvested restricted shares outstanding (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Unrecognized compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Unrecognized compensation expense, recognition period Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Stock-based compensation expense (less than $0.1 million in 2016) Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost Net Income Per Share Earnings Per Share [Text Block]