Document and Entity Information [Abstract] Document and Entity Information [Abstract] Statement [Table] Statement [Table] Class Of Stock [Axis] Class of Stock [Axis] Class Of Stock [Domain] Class of Stock [Domain] Class Units Member Class A units Represents class A of limited liability company account. Class B Units Member Class B units Represents class B of limited liability company account. Statement [Line Items] Statement [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Entity Current Reporting Status Entity Current Reporting Status Entity Voluntary Filers Entity Voluntary Filers Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Statement Of Financial Position [Abstract] Statement of Financial Position [Abstract] Assets [Abstract] Assets Assets, Current [Abstract] Current assets: Cash and Cash Equivalents, At Carrying Value Cash and cash equivalents Cash and cash equivalents Cash and cash equivalents at beginning of the period Cash and cash equivalents at end of the period Due From Affiliate, Current Due from affiliates Other Receivables Other receivables Assets, Current Total current assets Total current assets Property, Plant and Equipment, Gross Property, plant, and equipment, at cost Property, plant, and equipment, at cost Property, Plant and Equipment, Gross, Beginning Balance Property, Plant and Equipment, Gross, Ending Balance Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Less accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Total Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Beginning Balance Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Ending Balance Less accumulated depreciation Property, Plant and Equipment, Net Net property, plant, and equipment Net property, plant, and equipment Property, Plant and Equipment, Net, Beginning Balance Property, Plant and Equipment, Net, Ending Balance Investments In and Advance To Affiliates, Subsidiaries, Associates, and Joint Ventures Investment in National Beef Packing Company, LLC Investments in National Beef Packing Company, LLC Restricted Cash and Cash Equivalents, Noncurrent Restricted cash Other Assets, Noncurrent Other assets Other Assets, Noncurrent, Total Assets Total assets Total assets Liabilities and Equity [Abstract] Liabilities and Capital Shares and Equities Liabilities, Current [Abstract] Current liabilities: Accounts Payable, Trade, Current Accounts payable - trade Due To Affiliate, Current Due to affiliates Employee-Related Liabilities, Current Accrued compensation and benefits Employee-related Liabilities, Current, Total Other Accrued Liabilities, Current Other accrued expenses and liabilities Patronage Notice Payable In Cash Patronage notices payable in cash Total of patronage notice payable in cash. Distributions Payable Distributions payable Total amount of distributions payable. Liabilities, Current Total current liabilities Total current liabilities Liabilities, Noncurrent [Abstract] Long-term liabilities: Employee Related Liabilities Noncurrent Accrued compensation and benefits Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the noncurrent portion of the liabilities due after one year (or the normal operating cycle, if longer). Liabilities Total liabilities Total liabilities Stockholders Equity, Including Portion Attributable To Noncontrolling Interest [Abstract] Capital shares and equities: Members Capital Member's capital Balance at December 31, 2011 Balance at September 29, 2012 The amount of ownership interest of different classes of members in the limited liability company. Members' capital, 735,385 Class A units and 755,385 Class B units authorized, issued and outstanding Liabilities and Capital Shares and Equities Total liabilities and capital shares and equities Total liabilities and capital shares and equities Total of all Liabilities and Capital Shares and Equities items, including the portion of equity attributable to noncontrolling interests. Limited Liability Company Capital Account Units Authorized Members Capital, units authorized The number of limited liability company units authorized to be issued. Limited Liability Company Capital Account Units Issued Members Capital, units issued The number of limited liability company units issued. Limited Liability Company Capital Account Units Outstanding Members Capital, units outstanding The number of limited liability company units outstanding. Income Statement [Abstract] Income Statement [Abstract] Net Sales Net sales Net sales Costs and Expenses Costs and expenses: Cost Of Sales Cost of sales Cost of sales Selling, General, and Administrative Expenses Selling, general, and administrative expenses Selling, general, and administrative expenses Depreciation and Amortization Depreciation and amortization Depreciation and amortization Total Costs and Expenses Total costs and expenses Total costs and expenses Operating (Loss) Income Operating income Operating (loss) income Other Income (Expense) Other income (expense): Interest Income Interest income Interest income Interest Expense Interest expense Interest expense Interest expense Equity Interest In Net Income Of Subsidiary Equity interest in net income of National Beef Packing Company, LLC This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. Equity in net income of National Beef Packing Company, LLC Equity interest in net loss of National Beef Packing Company, LLC Other, Net Other, net Other, net Other, net Income Before Taxes Allocation of net income for the thirty-nine week period ended September 29, 2012 Income before taxes Income before taxes Income Tax Expense Income tax expense Income tax expense Net Income Net income Allocation of net income for the year Net income Net Income Less Net Income Attributable To Noncontrolling Interest In Less: Net income attributable to noncontrolling interest in: Net Income (Loss) Attributable To Noncontrolling Interest One Less: net income (loss) attributable to Kansas City Steak Company, LLC Kansas City Steak Company, LLC The portion of net Income or Loss attributable to the noncontrolling interest in subsidiary. Less: net income (loss) attributable to Kansas City Steak Company, LLC Net Income (Loss) Attributable To Noncontrolling Interest Two National Beef Packing Company, LLC Net income attributable to NBP The portion of net Income or Loss attributable to the noncontrolling interest in subsidiary. Net (loss) income attributable to NBP Net Income Attributable To U.S. Premium Beef, Llc NBP's net income attributable to USPB Allocation of net income for the year Net income attributable to U.S. Premium Beef, LLC (Loss) Earnings Per Unit Earnings per unit: Earnings Per Limited Liability Company Unit [Abstract] Basic income per unit Basic Per unit amount Net Income Loss Per Outstanding Limited Liability Company Class Unit Basic Class A units (in dollars per unit) Net income (loss) allocated to each outstanding limited liability company Class A unit. Net Income Loss Per Outstanding Limited Liability Company Class B Unit Basic Class B units (in dollars per unit) Net income (loss) allocated to each outstanding limited liability company Class B unit. Net Income Loss Per Outstanding Limited Liability Company Unit Diluted [Abstract] Diluted income per unit: Diluted Per unit amount Net Income Loss Per Outstanding Limited Liability Company Class Unit Diluted Class A Units (in dollars per unit) Net income or loss allocated to each limited liability company unit outstanding during the reporting period and Class A unit that would have been outstanding assuming the issuance of limited liability company units for all dilutive potential units outstanding during the reporting period. Net Income Loss Per Outstanding Limited Liability Company Class B Unit Diluted Class B Units (in dollars per unit) Net income or loss allocated to each limited liability company unit outstanding during the reporting period and Class B unit that would have been outstanding assuming the issuance of limited liability company units for all dilutive potential units outstanding during the reporting period. Weighted Average Number Of Units Outstanding [Abstract] Outstanding weighted-average Class A and Class B units: Weighted Average Number Of Units Outstanding Basic [Abstract] Basic Weighted average outstanding units (denominator) Weighted Average Limited Liability Company Class Units Outstanding Basic Class A units (in units) Class A (in units) The average number of limited liability company Class A units issued and outstanding that are used in calculating basic earnings per unit. Weighted average outstanding Class A units (in units) Weighted Average Limited Liability Company Class B Units Outstanding Basic Class B units (in units) Class B (in units) The average number of limited liability company Class B units issued and outstanding that are used in calculating basic earnings per unit. Weighted average outstanding Class B units (in units) Weighted Average Number Of Units Outstanding Diluted [Abstract] Diluted Weighted Average Limited Liability Company Class Units Outstanding Diluted Class A units (in units) Units (denominator) (in units) The average number of limited liability Class A company units issued and outstanding that are used in calculating diluted earnings per unit. Weighted Average Limited Liability Company Class B Units Outstanding Diluted Class B units (in units) Units (denominator) The average number of limited liability Class B company units issued and outstanding that are used in calculating diluted earnings per unit. Statement Of Income and Comprehensive Income [Abstract] Statement of Income and Comprehensive Income [Abstract] Other Comprehensive Income (Loss), Net Of Tax [Abstract] Other comprehensive income: Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net Of Tax Foreign currency translation adjustments Foreign currency translation adjustment Comprehensive Income (Loss), Net Of Tax, Including Portion Attributable To Noncontrolling Interest Comprehensive income Comprehensive income Comprehensive Income (Loss), Net Of Tax, Attributable To Noncontrolling Interest [Abstract] Comprehensive income attibutable to noncontrolling interest in: Comprehensive Income (Loss), Net Of Tax, Attributable To Parent Comprehensive income attributable to USPB Comprehensive income attributable to USPB Statement Of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Net Cash Provided By (Used In) Operating Activities, Continuing Operations [Abstract] Cash flows from operating activities: Adjustments To Reconcile Net Income (Loss) To Cash Provided By (Used In) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Distribution From Member Or Limited Partner, Cash Distribution Distribution from National Beef Packing Company, LLC The amount of cash distributions received from a common shareholder or unit-holder by a LLC or LP. Gain (Loss) On Sale Of Property Plant Equipment Gain on disposal of property, plant, and equipment Equity in earnings of National Beef Packing Company, LLC Loss on disposal of property, plant, and equipment Amortization Of Financing Costs Amortization of debt issuance costs Increase (Decrease) In Operating Capital [Abstract] Changes in assets and liabilities: Increase (Decrease) In Accounts Receivable Accounts receivable Accounts receivable Increase (Decrease) In Due From Affiliates, Current Due from affiliates Due from affiliates Increase (Decrease) In Other Receivables Other receivables Other receivables Increase (Decrease) In Inventories Inventories Inventories Inventories Increase (Decrease) In Prepaid Expense and Other Assets Other assets Other assets Other assets Increase Decrease In Cattle Purchases Payable Cattle purchases payable The increase (decrease) during the reporting period in cattle purchases payable. Increase (Decrease) In Accounts Payable Accounts payable Accounts payable Increase (Decrease) In Due To Affiliates, Current Due to affiliates Increase (Decrease) In Employee Related Liabilities Accrued compensation and benefits Accrued compensation and benefits Increase Decrease In Accrued Insurance Accrued insurance The increase (decrease) during the reporting period in accrued insurance. Increase (Decrease) In Other Accrued Liabilities Other accrued expenses and liabilities Net Cash Provided By (Used In) Operating Activities, Continuing Operations Net cash provided by operating activities Net cash provided by operating activities Net Cash Provided By (Used In) Investing Activities, Continuing Operations [Abstract] Cash flows from investing activities: Payments To Acquire Property, Plant, and Equipment Capital expenditures, including interest capitalized Capital expenditures, including interest capitalized Capital expenditures, including interest capitalized Proceeds From Sale Of Property, Plant, and Equipment Proceeds from sale of property, plant, and equipment Proceeds from sale of property, plant, and equipment Net Cash Provided By (Used In) Investing Activities, Continuing Operations Net cash provided by (used in) investing activities Net cash used in investing activities Net Cash Provided By (Used In) Financing Activities, Continuing Operations [Abstract] Cash flows from financing activities: Proceeds From (Repayments Of) Lines Of Credit Net receipts under revolving credit lines Proceeds from (Repayments of) Lines of Credit, Total Net receipts under revolving credit lines Payments Of Notes Payable and Fees Payments of notes payable and fees The cash outflow for a borrowing supported by a written promise and fees to pay an obligation. Payments of term notes payable Proceeds From Notes Payable Borrowings of term notes payable Borrowings of term notes payable Repayments Of Other Debt and Capital Lease Obligations Repayments of other indebtedness/capital leases The cash outflow during the period from the repayment of other debt and payment of capital lease obligations. Repayments of other indebtedness / capital leases Payment Of Patronage Notices Payments of patronage notices The cash outflow for patronage notices. Payments of patronage notices Change In Overdraft Balances Change in overdraft balances This is the net cash inflow or outflow associated with checks that have been issued, but have not yet cleared. Distribution Made To Member Or Limited Partner, Cash Distributions Paid Distributions to non-controlling interests in National Beef Packing Company, LLC Distributions to noncontrolling interests in National Beef Packing Company, LLC Member Distribution Member distributions The cash outflow from members distribution. Member distributions Net Cash Provided By (Used In) Financing Activities, Continuing Operations Net cash used in financing activities Net cash used in financing activities Effect Of Exchange Rate On Cash and Cash Equivalents, Continuing Operations Effect of exchange rate changes on cash Cash and Cash Equivalents, Period Increase (Decrease) Net increase (decrease) in cash Net (decrease) increase in cash Interim Financial Statements [Abstract] Interim Financial Statements [Abstract] Basis Of Accounting [Text Block] Interim Financial Statements Members Capital [Abstract] Members Capital [Abstract] Members Capital [Text Block] Members' Capital The entire disclosure for the reconciliation of members capital during the period. Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Text Block] Disclosure about Derivative Instruments and Hedging Activities Earnings Per Share [Text Block] Income Attributable to USPB Per Unit Investments In and Advances To Affiliates, Schedule Of Investments [Abstract] Investments in and Advances to Affiliates, Schedule of Investments [Abstract] Investments In and Advances To Affiliates, Schedule Of Investments [Text Block] Investment in National Beef Packing Company, LLC Prior Period Adjustment [Abstract] Prior Period Adjustment [Abstract] Accounting Changes and Error Corrections [Text Block] Immaterial Prior Period Error Basis Of Accounting, Policy [Policy Text Block] Basis of Presentation Reconciliation Of Members Capital [Table Text Block] Schedule of reconciliation of Members Capital The entire tabular disclosure for beginning balance of members capital changes during the year and ending balance. Schedule Of Derivatives Instruments Statements Of Financial Performance and Financial Position, Location [Table Text Block] Schedule of the impact of derivative instruments on the Consolidated Statement of Operations Schedule Of Income Per Unit Calculation Table [Text Block] Schedule of Income Per Unit Calculation Tabular disclosure of the numerators and the denominators of the basic and diluted per-share (or per-unit) computations for income from continuing operations, including the effect that has been given to preferred dividends, if any. Schedule Of Investment Under Equity Method Accounting [Table Text Block] Schedule of summary of the results of operations for NBP Statement of operations for the company in which the filer has an investment that is carried under the equity method of accounting. Schedule Of Error Corrections and Prior Period Adjustments [Table Text Block] Schedule of immaterial adjustment recorded in the consolidated financial statements Noncontrolling Interest [Table] Noncontrolling Interest [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Leucadia National Corporation [Member] Leucadia National Corporation (Leucadia) Company which is controlled, directly or indirectly, by its parent. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. Controlling and Noncontrolling Interest [Line Items] Controlling And Noncontrolling Interest [Line Items] This element represents controlling and noncontrolling interest of an entity. Membership Interest Ownership Percentage By Noncontrolling Owners Purchase of membership interests in National Beef Packing Company, LLC (NBP) The percentage of ownership interests sold to another party. Equity Method Investment, Ownership Percentage Remaining membership interests in National Beef Packing Company, LLC (NBP) Increase (Decrease) In Stockholders' Equity [Roll Forward] Members Capital [Roll Forward] Limited Partners' Capital Account, Distribution Amount Member distributions Derivative Instruments, Gain (Loss) By Hedging Relationship, By Income Statement Location, By Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not Designated As Hedging Instrument [Member] Derivatives Not Designated as Hedging Instruments Trading Activity [Axis] Trading Activity [Axis] Trading Activity, By Type [Domain] Trading Activity, by Type [Domain] Commodity [Member] Commodity contracts Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Sales [Member] Location of Gain (Loss) Recognized in Income on Derivatives - Net sales Cost Of Sales [Member] Location of Gain (Loss) Recognized in Income on Derivatives - Cost of sales Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) Recognized In Income, Net Amount of Gain (Loss) Recognized in Income On Derivatives Percentage Of Income Allocated To Unit Holders Percentage of Income allocated to Class A unit holders This represents the percentage of income allocated to limited liability Class A unit holders. Percentage Of Income Allocated To Class B Unit Holders Percentage of Income allocated to Class B unit holders This represents the percentage of income allocated to limited liability Class B unit holders. Number Of Shares Ceo Can Purchase Number of shares CEO may purchase on termination or eighteen months after termination to Class A unitholders Number of units that CEO can purchase, upon mutual agreement of the board of the company and the CEO. Number Of Shares Converted Into Unit Appreciation Rights Number of shares converted into unit appreciation rights to Class A unitholders Number of shares that converted into Unit Appreciation Rights. Maximum Number Of Shares Purchase Or Converted Into Contractual Rights Maximum number of shares purchase or converted into contractual rights to Class A unitholders Maximum number of shares purchase or converted into contractual rights. Per Unit Price To Purchase Or Convert Contractual Rights Into Class Units Per unit price to purchase or convert contractual rights to Class A unitholders (in dollars per unit) This represents the purchase price of unit or conversion price per unit of appreciation rights. Basic Income Per Unit Calculation [Abstract] Basic income per unit Diluted income per unit: Basic Income Per Unit Income Attributable To Uspb Available To Unitholders (Numerator) Basic income per unit : Income attributable to USPB available to unitholders (numerator) Net Income Attributable To Parent Available To Basic Class Class A The portion of profit or loss for the period, net of income taxes, which is attributable to the parent available to Class B. Net Income Attributable To Parent Available To Class B Class B The portion of profit or loss for the period, net of income taxes, which is attributable to the parent available to Class B. Diluted Income Per Unit Calculation [Abstract] Diluted income per unit: Income (Loss) From Operations Attributable To Parents [Abstract] Income attributable to USPB available to unitholders (numerator) Net Income Attributable To Parent Available To Class Diluted Class A The portion of profit or loss for the period, net of income taxes, which is attributable to the parent available to Class A diluted unitholders. Net Income Attributable To Parent Available To Class B Diluted Class B The portion of profit or loss for the period, net of income taxes, which is attributable to the parent available to Class B diluted unitholders. Effect Of Dilutive Securities Class Unit Options Effect of dilutive securities - Class A unit options (in units) Effect of dilutive securities -Class A unit options. Effect Of Dilutive Securities Class B Unit Options Effect of dilutive securities - Class B unit options (in units) Effect of dilutive securities -Class B unit options. Schedule Of Investments [Table] Schedule of Investments [Table] National Beef Packing Company Llc [Member] National Beef Packing Company, LLC This is an affiliate entity, accounted for using the equity method of accounting as the Company has the ability to exercise significant influence, but does not have financial or operational control. Schedule Of Investments [Line Items] Schedule of Investments [Line Items] Schedule Of Error Corrections and Prior Period Adjustment Restatement [Table] Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Scenario, Previously Reported [Member] Original Restatement Adjustment [Member] Adjustment Error Corrections and Prior Period Adjustments Restatement [Line Items] Error Corrections and Prior Period Adjustments Restatement [Line Items] Employee-Related Liabilities Accrued compensation and benefits Vesting Period Of Phantom Units Vesting period of management phantom units plan (in years) Period represents vesting term in years of management phantom units plan. Amendment Description