Significant Accounting Policies (Policies)	6 Months Ended
Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated balance sheet of Geospace Technologies Corporation and its subsidiaries (the “Company”) at September 30, 2020 was derived from the Company’s audited consolidated financial statements at that date. The consolidated balance sheet at March 31, 2021 and the consolidated statements of operations, comprehensive loss, stockholders’ equity and cash flows for the three and six months ended March 31, 2021 and 2020 were prepared by the Company without audit. In the opinion of management, all adjustments, consisting of normal recurring adjustments, necessary to present fairly the consolidated financial position, results of operations and cash flows were made. All intercompany balances and transactions have been eliminated. The results of operations for the three and six months ended March 31, 2021 are not necessarily indicative of the operating results for a full year or of future operations. Certain information and footnote disclosures normally included in financial statements presented in accordance with accounting principles generally accepted in the United States of America were omitted pursuant to the rules of the Securities and Exchange Commission. The accompanying consolidated financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the Company’s fiscal year ended September 30, 2020.
Reclassifications	Reclassifications Certain amounts previously presented in the consolidated financial statements have been reclassified to conform to the current year presentation. Such reclassifications had no effect on previously reported net loss, stockholders’ equity or cash flows.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires the use of estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company considers many factors in selecting appropriate operational and financial accounting policies and controls, and in developing the estimates and assumptions that are used in the preparation of these financial statements. The Company continually evaluates its estimates, including those related to bad debt reserves, collectability of rental revenue, inventory obsolescence reserves, self-insurance reserves, product warranty reserves, useful lives of long-lived assets, impairment of long-lived assets and intangible assets, contingent consideration, investment in debt security and deferred income tax assets. The Company bases its estimates on historical experience and various other factors that are believed to be reasonable under the circumstances. While management believes current estimates are reasonable and appropriate, actual results may differ from these estimates under different conditions or assumptions.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original or remaining maturity at the time of purchase of three months or less to be cash equivalents. At March 31, 2021, cash and cash equivalents included $5.3 million held by the Company’s foreign subsidiaries and branch offices. If the Company were to repatriate the cash held by its foreign subsidiaries, it could be required to accrue and pay taxes on any amount repatriated. The Tax Cut and Jobs Act (“2017 Tax Act”) creates new taxes on certain foreign earnings and also requires entities to pay a one-time transition tax on undistributed earnings of their foreign subsidiaries which were previously tax deferred. The Company has determined it is not required to pay transition tax on the undistributed earnings of its foreign subsidiaries since it had no accumulated foreign earnings on a consolidated basis.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (the “FASB”) issued guidance surrounding credit losses for financial instruments that replaces the incurred loss impairment methodology in generally accepted accounting principles. The new impairment model requires immediate recognition of estimated credit losses expected to occur for most financial assets and certain other financial instruments. For available-for-sale debt securities with unrealized losses, credit losses will be recognized as allowances rather than reductions in the amortized cost of the securities. As a small reporting company, the Company must adopt this standard no later than the first quarter of its fiscal year ending September 30, 2024. Early adoption is permitted. The standard’s provisions will be applied as a cumulative-effect adjustment to retained earnings as of the beginning of the first effective reporting period. The Company intends to adopt this standard during the first quarter of its fiscal year ending September 30, 2024 and is continuing to evaluate the impact of this new guidance on its consolidated financial statements. In December 2019, the FASB issued guidance on simplifying the accounting for income taxes. The guidance eliminates certain exceptions to the general principles in Topic 740 and clarifies and amends existing guidance to improve consistent application. This guidance is effective for fiscal years and interim periods within those fiscal years, beginning after December 15, 2020. Certain amendments within the guidance are required to be applied on a retrospective basis for all periods presented; others are to be applied using a modified retrospective approach with a cumulative-effect adjustment to retained earnings, if any, as of the beginning of the first reporting period in which the guidance is adopted; and yet others are to be applied using either basis. All other amendments not specified in the guidance should be applied on a prospective basis. Early adoption is permitted. An entity that elects to early adopt in an interim period should reflect any adjustments as of the beginning of the annual period that includes that interim period. Additionally, an entity that elects early adoption must adopt all the amendments in the same period. The Company intends to adopt this standard during the first quarter of its fiscal year ending September 30, 2022 and is continuing to evaluate the new guidance to determine the impact it will have on its condensed consolidated financial statements.

Significant Accounting Policies (Policies)

6 Months Ended

Mar. 31, 2021

The consolidated balance sheet of Geospace Technologies Corporation and its subsidiaries (the “Company”) at September 30, 2020 was derived from the Company’s audited consolidated financial statements at that date. The consolidated balance sheet at March 31, 2021 and the consolidated statements of operations, comprehensive loss, stockholders’ equity and cash flows for the three and six months ended March 31, 2021 and 2020 were prepared by the Company without audit. In the opinion of management, all adjustments, consisting of normal recurring adjustments, necessary to present fairly the consolidated financial position, results of operations and cash flows were made. All intercompany balances and transactions have been eliminated. The results of operations for the three and six months ended March 31, 2021 are not necessarily indicative of the operating results for a full year or of future operations.

Certain information and footnote disclosures normally included in financial statements presented in accordance with accounting principles generally accepted in the United States of America were omitted pursuant to the rules of the Securities and Exchange Commission. The accompanying consolidated financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the Company’s fiscal year ended September 30, 2020.

Reclassifications

Certain amounts previously presented in the consolidated financial statements have been reclassified to conform to the current year presentation. Such reclassifications had no effect on previously reported net loss, stockholders’ equity or cash flows.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires the use of estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company considers many factors in selecting appropriate operational and financial accounting policies and controls, and in developing the estimates and assumptions that are used in the preparation of these financial statements. The Company continually evaluates its estimates, including those related to bad debt reserves, collectability of rental revenue, inventory obsolescence reserves, self-insurance reserves, product warranty reserves, useful lives of long-lived assets, impairment of long-lived assets and intangible assets, contingent consideration, investment in debt security and deferred income tax assets. The Company bases its estimates on historical experience and various other factors that are believed to be reasonable under the circumstances. While management believes current estimates are reasonable and appropriate, actual results may differ from these estimates under different conditions or assumptions.

Cash and Cash Equivalents

The Company considers all highly liquid investments purchased with an original or remaining maturity at the time of purchase of three months or less to be cash equivalents. At March 31, 2021, cash and cash equivalents included $5.3 million held by the Company’s foreign subsidiaries and branch offices. If the Company were to repatriate the cash held by its foreign subsidiaries, it could be required to accrue and pay taxes on any amount repatriated. The Tax Cut and Jobs Act (“2017 Tax Act”) creates new taxes on certain foreign earnings and also requires entities to pay a one-time transition tax on undistributed earnings of their foreign subsidiaries which were previously tax deferred. The Company has determined it is not required to pay transition tax on the undistributed earnings of its foreign subsidiaries since it had no accumulated foreign earnings on a consolidated basis.

Recently Issued Accounting Pronouncements

In June 2016, the Financial Accounting Standards Board (the “FASB”) issued guidance surrounding credit losses for financial instruments that replaces the incurred loss impairment methodology in generally accepted accounting principles. The new impairment model requires immediate recognition of estimated credit losses expected to occur for most financial assets and certain other financial instruments. For available-for-sale debt securities with unrealized losses, credit losses will be recognized as allowances rather than reductions in the amortized cost of the securities. As a small reporting company, the Company must adopt this standard no later than the first quarter of its fiscal year ending September 30, 2024. Early adoption is permitted. The standard’s provisions will be applied as a cumulative-effect adjustment to retained earnings as of the beginning of the first effective reporting

period. The Company intends to adopt this standard during the first quarter of its fiscal year ending September 30, 2024 and is continuing to evaluate the impact of this new guidance on its consolidated financial statements.

In December 2019, the FASB issued guidance on simplifying the accounting for income taxes. The guidance eliminates certain exceptions to the general principles in Topic 740 and clarifies and amends existing guidance to improve consistent application. This guidance is effective for fiscal years and interim periods within those fiscal years, beginning after December 15, 2020. Certain amendments within the guidance are required to be applied on a retrospective basis for all periods presented; others are to be applied using a modified retrospective approach with a cumulative-effect adjustment to retained earnings, if any, as of the beginning of the first reporting period in which the guidance is adopted; and yet others are to be applied using either basis. All other amendments not specified in the guidance should be applied on a prospective basis. Early adoption is permitted. An entity that elects to early adopt in an interim period should reflect any adjustments as of the beginning of the annual period that includes that interim period. Additionally, an entity that elects early adoption must adopt all the amendments in the same period. The Company intends to adopt this standard during the first quarter of its fiscal year ending September 30, 2022 and is continuing to evaluate the new guidance to determine the impact it will have on its condensed consolidated financial statements.