SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of Barnwell Industries, Inc. and all majority-owned subsidiaries (collectively referred to herein as “Barnwell,” “we,” “our,” “us,” or the “Company”), including a 77.6%-owned land investment general partnership (Kaupulehu Developments), a 75%-owned land investment partnership (KD Kona 2013 LLLP), and a variable interest entity (Teton Barnwell Fund I, LLC) for which the Company is deemed to be the primary beneficiary. All significant intercompany accounts and transactions have been eliminated. Undivided interests in oil and natural gas exploration and production joint ventures are consolidated on a proportionate basis. Barnwell’s investments in both unconsolidated entities in which a significant, but less than controlling, interest is held and in variable interest entities in which the Company is not deemed to be the primary beneficiary are accounted for by the equity method. Unless otherwise indicated, all references to “dollars” in this Form 10-Q are to U.S. dollars.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying unaudited condensed consolidated financial statements and notes have been prepared by Barnwell in accordance with the rules and regulations of the United States (“U.S.”) Securities and Exchange Commission. Accordingly, certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been condensed or omitted pursuant to those rules and regulations, although the Company believes that the disclosures made are adequate to make the information not misleading. These condensed consolidated financial statements and notes should be read in conjunction with the consolidated financial statements and notes thereto included in Barnwell’s September 30, 2022 Annual Report on Form 10-K, as amended by our Form 10-K/A Amendment No. 1 (our “2022 Annual Report”). The Condensed Consolidated Balance Sheet as of September 30, 2022 has been derived from audited consolidated financial statements. In the opinion of management, all adjustments (which include only normal recurring adjustments, with the exception of an out-of-period adjustment for the six months ended March 31, 2023 as described below) necessary to present fairly the financial position at March 31, 2023, results of operations, comprehensive (loss) income, and equity for the three and six months ended March 31, 2023 and 2022, and cash flows for the six months ended March 31, 2023 and 2022, have been made. The results of operations for the period ended March 31, 2023 are not necessarily indicative of the operating results for the full year.
Out-of-Period Adjustment	Out-of-Period Adjustment During the three months ended December 31, 2022, errors were identified related to estimates of accrued oil and natural gas sales and accrued professional fees for the year ended September 30, 2022. Accordingly, the Company recorded out-of-period adjustments in the three months ended December 31, 2022 for the rollover effect of those differences which were immaterial to the results of that quarter. For the six months ended March 31, 2023, the rollover effect of those out-of-period adjustments both decreased oil and natural gas revenues and increased general and administrative expenses by a total of $147,000, which accordingly increased our net loss before income taxes and net loss for the six months ended March 31, 2023 by the same amount. The net earnings per basic and diluted share attributable to Barnwell stockholders would have been $0.02 lower for the year ended September 30, 2022 and the net loss per basic and diluted share attributable to Barnwell stockholders would have been $0.01 lower for the six months ended March 31, 2023 had the amounts been reflected in the periods to which they relate. Based upon an evaluation of all relevant quantitative and qualitative factors, and after considering the provisions of Staff Accounting Bulletin (SAB) No. 99, “Materiality,” and SAB 108, management believes these out-of-period correcting adjustments were not material to the Company’s results for the six months ended March 31, 2023 or the Company’s trend of operating results. We evaluated the impact of these out-of-period adjustments on the results of our previously issued financial statements for the year ended September 30, 2022 and first quarter ended December 31, 2022 and concluded that the impact was not material as well.
Use of Estimates in the Preparation of Condensed Consolidated Financial Statements	Use of Estimates in the Preparation of Condensed Consolidated Financial Statements The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management of Barnwell to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ significantly from those estimates. Significant assumptions are required in the valuation of deferred tax assets, asset retirement obligations, share-based payment arrangements, obligations for retirement plans, contract drilling estimated costs to complete, proved oil and natural gas reserves, and the carrying value of other assets, and such assumptions may impact the amount at which such items are recorded.
Advances To Operators For Capital Expenditures	Advances to Operators for Capital Expenditures The Company participates in the drilling of crude oil and natural gas wells with other working interest partners. Due to the capital-intensive nature of crude oil and natural gas drilling activities, the working interest partner responsible for conducting the drilling operations may request advance payments from other working interest partners for their share of the costs. The Company expects such advances to be applied by working interest partners against joint interest billings for its share of drilling operations within 90 days from when the advance is paid.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

6 Months Ended

Mar. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The condensed consolidated financial statements include the accounts of Barnwell Industries, Inc. and all majority-owned subsidiaries (collectively referred to herein as “Barnwell,” “we,” “our,” “us,” or the “Company”), including a 77.6%-owned land investment general partnership (Kaupulehu Developments), a 75%-owned land investment partnership (KD Kona 2013 LLLP), and a variable interest entity (Teton Barnwell Fund I, LLC) for which the Company is deemed to be the primary beneficiary. All significant intercompany accounts and transactions have been eliminated.

Undivided interests in oil and natural gas exploration and production joint ventures are consolidated on a proportionate basis. Barnwell’s investments in both unconsolidated entities in which a significant, but less than controlling, interest is held and in variable interest entities in which the Company is not deemed to be the primary beneficiary are accounted for by the equity method.

Unless otherwise indicated, all references to “dollars” in this Form 10-Q are to U.S. dollars.

Unaudited Interim Financial Information

The accompanying unaudited condensed consolidated financial statements and notes have been prepared by Barnwell in accordance with the rules and regulations of the United States (“U.S.”) Securities and Exchange Commission. Accordingly, certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been condensed or omitted pursuant to those rules and regulations, although the Company believes that the disclosures made are adequate to make the information not misleading. These condensed consolidated financial statements and notes should be read in conjunction with the consolidated financial statements and notes thereto included in Barnwell’s September 30, 2022 Annual Report on Form 10-K, as amended by our Form 10-K/A Amendment No. 1 (our “2022 Annual Report”). The Condensed Consolidated Balance Sheet as of September 30, 2022 has been derived from audited consolidated financial statements.

In the opinion of management, all adjustments (which include only normal recurring adjustments, with the exception of an out-of-period adjustment for the six months ended March 31, 2023 as described below) necessary to present fairly the financial position at March 31, 2023, results of operations, comprehensive (loss) income, and equity for the three and six months ended March 31, 2023 and 2022, and cash flows for the six months ended March 31, 2023 and 2022, have been made. The results of operations for the period ended March 31, 2023 are not necessarily indicative of the operating results for the full year.

Out-of-Period Adjustment

During the three months ended December 31, 2022, errors were identified related to estimates of accrued oil and natural gas sales and accrued professional fees for the year ended September 30, 2022.

Accordingly, the Company recorded out-of-period adjustments in the three months ended December 31, 2022 for the rollover effect of those differences which were immaterial to the results of that quarter. For the six months ended March 31, 2023, the rollover effect of those out-of-period adjustments both decreased oil and natural gas revenues and increased general and administrative expenses by a total of $147,000, which accordingly increased our net loss before income taxes and net loss for the six months ended March 31, 2023 by the same amount. The net earnings per basic and diluted share attributable to Barnwell stockholders would have been $0.02 lower for the year ended September 30, 2022 and the net loss per basic and diluted share attributable to Barnwell stockholders would have been $0.01 lower for the six months ended March 31, 2023 had the amounts been reflected in the periods to which they relate. Based upon an evaluation of all relevant quantitative and qualitative factors, and after considering the provisions of Staff Accounting Bulletin (SAB) No. 99, “Materiality,” and SAB 108, management believes these out-of-period correcting adjustments were not material to the Company’s results for the six months ended March 31, 2023 or the Company’s trend of operating results. We evaluated the impact of these out-of-period adjustments on the results of our previously issued financial statements for the year ended September 30, 2022 and first quarter ended December 31, 2022 and concluded that the impact was not material as well.

Use of Estimates in the Preparation of Condensed Consolidated Financial Statements

The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management of Barnwell to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ significantly from those estimates. Significant assumptions are required in the valuation of deferred tax assets, asset retirement obligations, share-based payment arrangements, obligations for retirement plans, contract drilling estimated costs to complete, proved oil and natural gas reserves, and the carrying value of other assets, and such assumptions may impact the amount at which such items are recorded.

Advances To Operators For Capital Expenditures

Advances to Operators for Capital Expenditures

The Company participates in the drilling of crude oil and natural gas wells with other working interest partners. Due to the capital-intensive nature of crude oil and natural gas drilling activities, the working interest partner responsible for conducting the drilling operations may request advance payments from other working interest partners for their share of the costs. The Company expects such advances to be applied by working interest partners against joint interest billings for its share of drilling operations within 90 days from when the advance is paid.