Equity Components [Axis] Common Stock Additional Paid-In Capital Retained Earnings Accumulated Other Comprehensive Income (Loss) Treasury Stock Indefinite-lived Intangible Assets by Major Class [Axis] Franchise Agreement Asset Class [Axis] Finite-Lived Intangible Assets [Member] Other Indefinite-lived Intangible Assets [Member] Trade names [Member] Fair Value, Hierarchy [Axis] Level 1 Level 2 Level 3 Products and Services [Axis] Restaurant Income Statement Location [Axis] Steak n Shake Western Total Restaurant Operations Reconciliation Of Segments Interest expense on notes payable and other borrowings [Member] Business Segments [Axis] Steak n Shake Total Revenue Related Party [Axis] Lion Fund Lion Fund II Other Comprehensive Income Location [Axis] Foreign Currency Translation Adjustments Investment Gain (Loss) Securities Financing Transaction [Axis] Fair Value Company common Stock Carrying Value Derivative Instrument [Axis] Steak n Shake Agreement 2014 [Member] Debt Instrument [Axis] Term Loan Other First Guard Maxim Operating Business Corporate Investment Partnership Gains [Member] Other Total Corporate And Investments [Member] Corporate Class of Stock [Axis] Class A Common Stock Class B Common Stock Adjustments for Change in Accounting Principle [Axis] As Reported Adjustments for the Adoption of ASC 606 Amounts without Adoption of ASC 606 Statement [Table] Statement [Line Items] Entity Registrant Name Entity Central Index Key Document Type Document Period End Date Amendment Flag Current Fiscal Year End Date Is Entity a Well-known Seasoned Issuer Is Entity a Voluntary Filer Is Entity's Reporting Status Current Entity Filer Category Entity Common Stock, Shares Outstanding Document Fiscal Period Focus Document Fiscal Year Focus Statement of Financial Position [Abstract] Assets Current assets: Cash and cash equivalents Investments Receivables Inventories Other current assets Total current assets Property and equipment Goodwill and other intangible assets Investment partnerships Other assets Total assets Liabilities and shareholders' equity Liabilities Current liabilities: Accounts payable and accrued expenses Current portion of notes payable and other borrowings Total current liabilities Long-term notes payable and other borrowings Deferred taxes Other liabilities Total liabilities Shareholders' equity Common Stock Additional paid-in capital Retained earnings Accumulated other comprehensive loss Treasury stock, at cost Biglari Holdings Inc. shareholders' equity Total liabilities and shareholders' equity Common stock, shares outstanding Income Statement [Abstract] Revenues Restaurant operations Insurance premiums and other Media advertising and other Total revenues Cost and expenses Restaurant cost of sales Insurance losses and underwriting expenses Media cost of sales Selling, general and administrative Depreciation and amortization Total cost and expenses Other income (expenses) Interest expense Interest on obligations under leases Investment partnership gains (losses) Total other income (expenses) Earnings (losses) before income taxes Income tax benefit Net loss Earnings per share Net earnings per equivalent Class A share Consolidated Statements Of Comprehensive Income Net loss Other comprehensive income: Net change in unrealized gains and losses on investments Applicable income taxes Reclassification to earnings Applicable income taxes Foreign currency translation Other comprehensive income, net Total comprehensive loss Statement of Cash Flows [Abstract] Operating activities Net earnings (loss) Adjustments to reconcile net earnings (loss) to operating cash flows: Provision for deferred income taxes Asset impairments and other non-cash expenses Loss on disposal of assets Investment partnership gains/losses Distributions from investment partnerships Changes in receivables and inventories Changes in other assets Changes in accounts payable and accrued expenses Net cash provided by (used in) operating activities Investing activities Capital expenditures Proceeds from property and equipment disposals Purchases of investments Redemptions of fixed maturity securities Net cash used in investing activities Financing activities Payments on revolving credit facility Principal payments on long-term debt Principal payments on direct financing lease obligations Proceeds from exercise of stock options Net cash used in financing activities Effect of exchange rate changes on cash Decrease in cash, cash equivalents and restricted cash Cash, cash equivalents and restricted cash at beginning of year Cash, cash equivalents and restricted cash at end of third quarter Balance Net earnings (loss) Adoption of accounting standards Other comprehensive income, net Adjustment to treasury stock for holdings in investment partnerships Exercise of stock options Balance Accounting Policies [Abstract] Note 1. Summary of Significant Accounting Policies Note 2. New Accounting Standards Earnings Per Share [Abstract] Note 3. Earnings Per Share Schedule of Investments [Abstract] Note 4. Investments Note 5. Investment Partnerships Note 5. Investment Partnerships Property, Plant and Equipment [Abstract] Note 6. Property and Equipment Goodwill and Intangible Assets Disclosure [Abstract] Note 7. Goodwill and Other Intangible Assets Note 8. Restaurant Operations Revenues Note 8. Restaurant Operations Revenues Payables and Accruals [Abstract] Note 9. Accounts Payable and Accrued Expenses Debt Disclosure [Abstract] Note 10. Borrowings Equity [Abstract] Note 11. Accumulated Other Comprehensive Income Income Tax Disclosure [Abstract] Note 12. Income Taxes Commitments and Contingencies Disclosure [Abstract] Note 13. Commitments and Contingencies Fair Value Disclosures [Abstract] Note 14. Fair Value of Financial Assets Related Party Transactions [Abstract] Note 15. Related Party Transactions Segment Reporting [Abstract] Note 16. Business Segment Reporting Description of Business Principles of Consolidation Note 2. New Accounting Standards Tables Impact of new accounting pronouncements Summary of outstanding shares Schedule of fair value of Investments Note 5. Investment Partnerships Tables Fair value and carrying value of our partnership interest Carrying value of investment partnerships net of deferred taxes Gains (loss) from investment partnerships Summarized financial information for Equity in Investment Partnerships Schedule of Property, Plant and Equipment Schedule of Goodwill Schedule of Other Intangible Assets Note 8. Restaurant Operations Revenues Tables Summary of restaurant operations revenues Note 9. Accounts Payable And Accrued Expenses Tables Schedule of Accounts Payable and Accrued Expenses Schedule of notes payable and other borrowings Component of accumulated other comprehensive income Schedule Of Fair Value Assets Schedule Of Revenue by Segment Schedule of earnings (losses) before income taxes by segment Restaurant operations net sales Restaurant operations franchise royalties and fees Restaurant operations other Earnings (loss) before income taxes Income tax expense (benefit) Note 3. Earnings Per Share Details Common stock authorized Common stock issued Treasury stock held by the Company Outstanding shares Cost Gross unrealized gains Fair value Partnership interest, beginning Partnership interest, beginning Investment partnership gains (losses) Contributions (net of distributions) to investment partnerships Increase in proportionate share of Company stock held Partnership interest, ending Partnership interest, ending Note 5. Investment Partnerships Details 1 Carrying value of investment partnerships Deferred tax liability related to investment partnerships Carrying value of investment partnerships net of deferred taxes Note 5. Investment Partnerships Details 2 Gains (losses) on investment partnership Tax expense (benefit) Contributions to net earnings (loss) Total Assets Total Liabilities Revenue for the first quarter Earnings (loss) for the first quarter Biglari Holdings' Ownership Interest Note 5. Investment Partnerships Details Narrative Proportionate share of Company stock held by investment partnerships at cost Accrued incentive fee Land Buildings Land and leasehold improvements Equipment Construction in progress Property and equipment, gross Less accumulated depreciation and amortization Property and equipment, net Legal Entity [Axis] Balance at beginning of year Change in foreign exchange rates during first quarter 2018 Balance at end of period Indefinite-lived Intangible Assets [Axis] Gross carrying amount Accumulated amortization Total intangible assets Amortization expense Total annual amortization expense for 2019 Note 8. Restaurant Operations Revenues Details Net sales Franchise royalties and fees Other Restaurant operations revenue Notes to Financial Statements Accounts payable Gift card liability Salaries, wages, and vacation Taxes payable Workers' compensation and other self insurance accruals Deferred revenue Other Current portion of notes payable and other borrowings Notes payable Unamortized original issue discount Unamortized debt issuance costs Obligations under leases Western revolver Total current portion of notes payable and other borrowings Long-term notes payable and other borrowings Notes payable Unamortized original issue discount Unamortized debt issuance costs Obligations under leases Total long-term notes payable and other borrowings Outstanding debt Interest rate Standby letters of credit Cash deposited as collateral for casualty insurance Beginning Balance Other comprehensive income (loss) before reclassifications Reclassification to (earnings) loss Foreign currency translation Ending Balance Unrecognized tax benefits Assets Cash equivalents Equity securities: Consumer goods Bonds Options on equity securities Non-qualified deferred compensation plan investments Total assets at fair value Segments [Axis] Revenue Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. The aggregate amount of interest expense incurred on the Company's financing and capital lease obligations. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. The cash outflow for principal payments made on direct financing lease obligations. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. Custom Element. SteakNShakeRestaurantOperationsMember OtherSegmentMember OtherMember Corporate1Member Assets, Current Assets [Default Label] Liabilities, Current Liabilities [Default Label] Common Stock, Value, Issued Treasury Stock, Value Stockholders' Equity Attributable to Parent Liabilities and Equity Revenue, Net Costs and Expenses Interest Expense InterestOnObligationsUnderLeases Nonoperating Income (Expense) Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Other Comprehensive Income (Loss), Available-for-sale Securities, Tax ReclassificationOfInvestmentDepreciationInNetEarnings ApplicableIncomeTaxesReclassificationOfInvestmentDepreciationInNetEarnings Comprehensive Income (Loss), Net of Tax, Attributable to Parent Gain (Loss) on Disposition of Assets Increase (Decrease) in Inventories Increase (Decrease) in Other Operating Assets Net Cash Provided by (Used in) Operating Activities Payments to Acquire Property, Plant, and Equipment Payments to Acquire Investments Net Cash Provided by (Used in) Investing Activities Repayments of Lines of Credit Repayments of Long-term Debt PrincipalPaymentsOnDirectFinancingLeaseObligations Net Cash Provided by (Used in) Financing Activities Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents InvestmentPartnershipsDisclosure RestaurantOperationsRevenuesDisclosureTextBlock Treasury Stock, Shares Available-for-sale Securities, Amortized Cost Basis AvailableForSaleSecuritiesFairValueDisclosure1 Equity Method Investments, Fair Value Disclosure CarryingValueOfInvestmentPartnershipsNetOfDeferredTaxes Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Amount Equity Method Investment, Ownership Percentage Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Goodwill Other Accrued Liabilities, Current Notes Payable, Noncurrent Debt Instrument, Unamortized Discount Unamortized Debt Issuance Expense Long-term Debt and Capital Lease Obligations Foreign Currency Transaction Loss, before Tax