Accrued capital expenditures Carrying value as of the balance sheet date of capital expenditure obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Accrued Capital Expenditures, Current Sale of interest in leasehold land, net Net revenue from the sale of interest in leasehold land. Sale of Interest in Leasehold Land, Net. Sale of interest in leasehold land, net Sale of development rights, net Sale of Development Rights, Net This element represents net revenue received from sale of development rights. Sale of development rights, net Gain from drilling royalty credits Gain from Drilling Royalty Credits This element represents the gain from purchases of Alberta drilling royalty credits for less than par value from third parties that had drilling royalty credits in excess of their formulaic maximum. Gas processing and other Gas Gathering, Transportation, Marketing, Processing and Other Revenue, Net Revenue related to midstream and downstream gas activities. May include the following: gathering from wells, processing to remove impurities, storage, transmission, compression, the sale of natural gas and related products and revenue from other services not otherwise specified in the taxonomy. Proceeds from sale of development rights, net of fees paid Proceeds from Sale Development Rights, Net This element represents cash net inflow from sale development rights during the reporting period. Proceeds from sale of interest in leasehold land, net of fees paid Proceeds from Sale of Interest in Leasehold Land, Net The cash inflow from the sale of interest in leasehold land, net of fees paid. Proceeds from gas over bitumen royalty adjustments Proceeds from Gas Over Bitumen Royalty This element represents cash inflow from gas over bitumen royalty adjustments during the reporting period. Cash inflow received as distributions, returns of capital, or sale proceeds from joint venture interests held for investment purposes. Return of capital distribution from joint venture Proceeds from Joint Venture Investments Contributions from non-controlling interests Proceeds from Non-controlling Interest Holders The cash inflow from the increase in noncontrolling interest balance due to contributions from noncontrolling interest holders. Contributions from non-controlling interests Payment of loan commitment fees Payment of Loan Commitment Fees This element represents cash outflow during the reporting period for payment of loan commitment fees. Payments to Noncontrolling Interest Holders Distributions to non-controlling interests The cash outflow from the decrease in noncontrolling interest balance due to payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders. REAL ESTATE HELD FOR SALE AND INVESTMENT IN RESIDENTIAL PARCELS Real Estate Held for Sale and Investment in Residential Parcels [Text Block] This element represents disclosure of investment in real estate and residential parcels. INVESTMENT IN JOINT VENTURES INVESTMENT IN JOINT VENTURES This element represents disclosure of investment in joint ventures. Investment in Joint Ventures [Text Block] INVESTMENT IN LAND INTERESTS INVESTMENT IN LAND INTERESTS Investment in Land Interests [Text Block] This element represents disclosure of investment in land interests. RESTRICTED CASH AND LONG-TERM DEBT Restricted Cash and Long-term Debt [Text Block] This element represents disclosure of restricted cash and complete disclosure of long-term contractual arrangements with lenders, including letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdown's on the line. FAIR VALUE MEASUREMENTS Equity Increase from Contributions from Non-controlling Interest Holders Contributions from non-controlling interests Increase in stockholders' equity balance due to contributions from noncontrolling interest holders. Document and Entity Information Exercise of stock options, shares (in shares) This element represents the gross number of shares of stock options exercised. Exercise of Stock Options Shares, Gross Exercise of stock options, shares tendered and placed in treasury (in shares) Stock Options Shares Tendered and Placed in Treasury This element represents the number of shares tendered to exercise options. INVESTMENTS INVESTMENTS Investment in Residential Parcels Joint Ventures and Land Interests Disclosure [Text Block] This element represents disclosure of investment in residential parcels, joint ventures, and land interests. CONSOLIDATED BALANCE SHEETS Allowance for Doubtful Accounts Receivable, Current Accounts receivable, allowance for doubtful accounts (in dollars) Common Stock, Par or Stated Value Per Share Common stock, par value (in dollars per share) Common Stock, Shares Authorized Common stock, authorized shares Common Stock, Shares, Issued Common stock, issued shares Treasury Stock, Shares Treasury stock, shares Statement [Table] Statement, Scenario [Axis] Scenario, Unspecified [Domain] Statement [Line Items] Statement Revenues [Abstract] Revenues: Oil and Gas Sales Revenue Oil and natural gas Contracts Revenue Contract drilling Revenues Total revenues Costs and Expenses [Abstract] Costs and expenses: Cost of Goods Sold, Oil and Gas Oil and natural gas operating Contract Revenue Cost Contract drilling operating General and Administrative Expense General and administrative Depreciation, Depletion and Amortization Depletion, depreciation, and amortization Depreciation, depletion, and amortization Asset Impairment Charges Reduction of carrying value of assets Foreign currency translation adjustments, net of taxes of $0 Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Foreign currency translation adjustments, net of taxes of $0 Interest Expense Interest expense Costs and Expenses Total costs and expenses Provision for Doubtful Accounts Bad debt expense Bad debt (recovery) expense Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Earnings before income taxes Income Tax Expense (Benefit) Income tax provision Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net earnings Net earnings (loss) Net earnings Net Income (Loss) Attributable to Noncontrolling Interest Less: Net earnings attributable to non-controlling interests Earnings Per Share, Basic Basic net (loss) earnings per common share attributable to Barnwell Industries, Inc. stockholders (in dollars per share) Earnings Per Share, Diluted Diluted net (loss) earnings per common share attributable to Barnwell Industries, Inc. stockholders (in dollars per share) Weighted Average Number of Shares Outstanding, Diluted [Abstract] Weighted-average number of common shares outstanding: Weighted Average Number of Shares Outstanding, Basic Basic (in shares) Weighted Average Number of Shares Outstanding, Diluted Diluted (in shares) CONSOLIDATED STATEMENTS OF OPERATIONS Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Cash and cash equivalents at beginning of year Cash and cash equivalents at end of year 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 earnings to net cash provided by operating activities: Share-based Compensation Share-based compensation expense Pension and Other Postretirement Benefit Expense Retirement benefits expense Deferred Income Tax Expense (Benefit) Deferred income tax expense Asset Retirement Obligation, Accretion Expense Accretion of asset retirement obligation Employee Service Share-based Compensation, Cash Flow Effect, Cash Used to Settle Awards Share-based compensation payments Pension and Other Postretirement Benefit Contributions Retirement plan contributions Payments to Acquire Held-for-sale Real Estate Additions to real estate held for sale Increase (Decrease) in Operating Capital Increase (decrease) from changes in current assets and liabilities Foreign exchange gain Foreign Currency Transaction Gain (Loss), before Tax Asset Retirement Obligation, Cash Paid to Settle Asset retirement obligation payments Net Cash Provided by (Used in) Operating Activities, Continuing Operations Net cash provided by operating activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Cash flows from investing activities: Proceeds from Sale of Oil and Gas Property and Equipment Proceeds from sale of oil and natural gas properties Payments to Acquire Other Property, Plant, and Equipment Capital expenditures - all other Proceeds from Deposits with Other Institutions Refund of deposits on residential parcels Payments to Acquire Interest in Joint Venture Investment in joint ventures Net Cash Provided by (Used in) Investing Activities, Continuing Operations Net cash (used in) provided by investing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Cash flows from financing activities: Repayments of Long-term Debt Repayments of long-term debt Proceeds from Stock Options Exercised Proceeds from exercise of stock options Other Comprehensive Income (Loss), Net of Tax Total other comprehensive income Proceeds from Issuance of Long-term Debt Proceeds from long-term debt borrowings Payments for Repurchase of Common Stock Purchases of common stock for treasury Net Cash Provided by (Used in) Financing Activities, Continuing Operations Net cash used in financing activities Effect of Exchange Rate on Cash and Cash Equivalents, Continuing Operations Effect of exchange rate changes on cash and cash equivalents Net Cash Provided by (Used in) Continuing Operations Net (decrease) increase in cash and cash equivalents CONSOLIDATED STATEMENTS OF CASH FLOWS SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES EARNINGS PER COMMON SHARE Earnings Per Share [Text Block] EARNINGS PER COMMON SHARE SHARE-BASED PAYMENTS Disclosure of Compensation Related Costs, Share-based Payments [Text Block] SHARE-BASED PAYMENTS REAL ESTATE HELD FOR SALE REAL ESTATE HELD FOR SALE Real Estate Disclosure [Text Block] LONG-TERM DEBT Long-term Debt [Text Block] LONG-TERM DEBT SEGMENT AND GEOGRAPHIC INFORMATION Segment Reporting Disclosure [Text Block] SEGMENT AND GEOGRAPHIC INFORMATION TAXES ON INCOME Income Tax Disclosure [Text Block] TAXES ON INCOME RETIREMENT PLANS Pension and Other Postretirement Benefits Disclosure [Text Block] RETIREMENT PLANS RELATED PARTY TRANSACTIONS Related Party Transactions Disclosure [Text Block] RELATED PARTY TRANSACTIONS SHARE REPURCHASE PROGRAM SHARE REPURCHASE PROGRAM Treasury Stock [Text Block] FAIR VALUE OF FINANCIAL INSTRUMENTS FAIR VALUE OF FINANCIAL INSTRUMENTS Fair Value Disclosures [Text Block] INFORMATION RELATING TO THE CONSOLIDATED STATEMENTS OF CASH FLOWS Cash Flow, Supplemental Disclosures [Text Block] INFORMATION RELATING TO THE CONSOLIDATED STATEMENTS OF CASH FLOWS OIL AND NATURAL GAS PROPERTIES Full Cost Method of Accounting for Investments in Oil and Gas Properties Disclosure [Text Block] OIL AND NATURAL GAS PROPERTIES Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity Total equity Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Balance Common Stock, Shares, Outstanding Balance (in shares) Balance (in shares) Stock Issued During Period, Value, Stock Options Exercised Exercise of stock options - 42,000 shares, net of 5,000 shares tendered and placed in treasury Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Exercise of stock options - 42,000 shares, net of 5,000 shares tendered and placed in treasury (in shares) Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Distributions to non-controlling interests Distributions to non-controlling interests Comprehensive Income, Net of Tax, Attributable to Parent [Abstract] Comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Other comprehensive income: Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax Amortization of accumulated other comprehensive loss into net periodic benefit cost, net of taxes of $0 Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Less: Comprehensive income attributable to non-controlling interests Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive income attributable to Barnwell Industries, Inc. Stockholders' Equity, Period Increase (Decrease) Stockholders' Equity Period Increase (Decrease) Stock Issued During Period, Shares, Period Increase (Decrease) Stock Issued During Period, Shares, Period Increase (Decrease) Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Share-based compensation costs Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Share-based compensation costs (in shares) Treasury Stock, Value, Acquired, Cost Method Purchases of 12,700 common shares for treasury Treasury Stock, Shares, Acquired Purchases of 12,700 common shares for treasury (in shares) Statement, Equity Components [Axis] Equity Component [Domain] Common Stock Additional Paid-In Capital Comprehensive Income (Loss) Retained Earnings Accumulated Other Comprehensive Income Treasury Stock Non-controlling Interests CONSOLIDATED STATEMENTS OF EQUITY Entity Registrant Name Entity Central Index Key Document Type Document Period End Date Amendment Flag Amendment Description Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Public Float Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Period Focus Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Foreign currency translation adjustments, taxes Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax Amortization of accumulated other comprehensive loss into net periodic benefit cost, taxes ACCUMULATED OTHER COMPREHENSIVE INCOME. Comprehensive Income Note [Text Block] ACCUMULATED OTHER COMPREHENSIVE INCOME SUBSEQUENT EVENTS SUBSEQUENT EVENTS Subsequent Events [Text Block] ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Restricted cash Restricted Cash and Cash Equivalents, Current Accounts receivable, net of allowance for doubtful accounts Accounts Receivable, Net, Current Income taxes receivable Income Taxes Receivable, Current Prepaid expenses Prepaid Expense, Current Real estate held for sale Inventory, Operative Builders Other current assets Other Assets, Current Total current assets Assets, Current Investments Long-term Investments Property and equipment Property, Plant and Equipment, Gross Total assets Assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued compensation Employee-related Liabilities, Current Payable to joint interest owners Accounts Payable, Other, Current Income taxes payable Accrued Income Taxes, Current Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accumulated depletion, depreciation, and amortization Other accrued compensation costs Other Employee Related Liabilities, Current Deferred Tax Liabilities, Noncurrent Deferred income taxes CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Retirement plans: Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract] Current portion of long-term debt Long-term Debt, Current Maturities Other current liabilities Other Liabilities, Current Total current liabilities Liabilities, Current Long-term debt Long-term Debt, Excluding Current Maturities Liability for retirement benefits Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Asset retirement obligation Asset Retirement Obligations, Noncurrent Deferred income taxes Deferred Tax Assets, Net, Current Total liabilities Liabilities Commitments and contingencies Commitments and Contingencies. Equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Barnwell Industries, Inc. stockholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Common stock, par value $0.50 per share; authorized, 20,000,000 shares: 8,445,060 issued at September 30, 2011 and 2010 Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income, net Accumulated Other Comprehensive Income (Loss), Net of Tax Treasury stock, at cost: 167,900 shares at September 30, 2011 and 2010 Treasury Stock, Value Total Barnwell Industries, Inc. stockholders' equity Stockholders' Equity Attributable to Parent Non-controlling interests Stockholders' Equity Attributable to Noncontrolling Interest Total liabilities and equity Liabilities and Equity Property, Plant and Equipment, Net Property and equipment, net Land Available for Development INVESTMENT IN RESIDENTIAL PARCELS Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures INVESTMENT IN JOINT VENTURES Land Improvements INVESTMENT IN LAND INTERESTS Commitments and Contingencies Disclosure [Text Block] COMMITMENTS AND CONTINGENCIES COMMITMENTS AND CONTINGENCIES Loans, Notes, Trade and Other Receivables Disclosure [Text Block] ACCOUNTS RECEIVABLE AND CONTRACT COSTS INCENTIVE COMPENSATION PLAN Concentration Risk Disclosure [Text Block] CONCENTRATIONS OF CREDIT RISK CONCENTRATIONS OF CREDIT RISK Quarterly Financial Information [Text Block] SUMMARY OF SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) SUMMARY OF SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) Oil and Gas Exploration and Production Industries Disclosures [Text Block] SUPPLEMENTARY OIL AND NATURAL GAS INFORMATION (UNAUDITED) SUPPLEMENTARY OIL AND NATURAL GAS INFORMATION (UNAUDITED) SIGNIFICANT ACCOUNTING POLICIES SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] PROPERTY AND EQUIPMENT AND ASSET RETIREMENT OBLIGATION PROPERTY AND EQUIPMENT AND ASSET RETIREMENT OBLIGATION Property and Equipment and Asset Retirement Obligation Disclosure [Text Block] Represents the entire disclosure for long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale and includes the disclosure for an asset retirement obligation. INCENTIVE COMPENSATION PLAN Incentive Compensation Plan Disclosure [Text Block] Represents the entire disclosure for an incentive compensation plan undertaken by the reporting entity for certain oil and natural gas segment personnel during the reporting period. Net (loss) earnings attributable to Barnwell Industries, Inc. Net Income (Loss) Available to Common Stockholders, Basic FAIR VALUE MEASUREMENTS Fair Value Measurement Disclosure [Text Block] Represents the entire disclosure of the fair value measurement of assets and liabilities which includes [financial] instruments measured at fair value that are classified in stockholders' equity. ACCOUNTS RECEIVABLE AND CONTRACT COSTS REDUCTION OF CARRYING VALUE OF ASSETS Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized (Gain) Loss Arising During Period, Net of Tax Net actuarial gains (losses) arising during the period, net of taxes of $0 Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Tax Net actuarial gains (losses) arising during the period, taxes Payments to Acquire Property, Plant, and Equipment Capital expenditures Asset Impairment Charges [Text Block] REDUCTION OF CARRYING VALUE OF ASSETS