Represents current assets over current liabilities.

No definition available.

Name:	geos_DebtInstrumentCovenantCurrentRatio
Namespace Prefix:	geos_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents EBIT over Interest expense.

+ References

No definition available.

+ Details

Name:	geos_DebtInstrumentCovenantInterestCoverageRatio
Namespace Prefix:	geos_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of minimum consolidated tangible net worth required under the covenant of the debt instrument.

+ References

No definition available.

+ Details

Name:	geos_DebtInstrumentCovenantMinimumConsolidatedTangibleNetWorth
Namespace Prefix:	geos_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of minimum liquidity required under the covenant of the debt instrument.

+ References

No definition available.

+ Details

Name:	geos_DebtInstrumentCovenantMinimumLiquidity
Namespace Prefix:	geos_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of certain accounts receivable as borrowing base under line of credit facility.

+ References

No definition available.

+ Details

Name:	geos_LineOfCreditFacilityBorrowingBaseAsPercentOfCertainAccountsReceivable
Namespace Prefix:	geos_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of eligible foreign insured amounts as borrowing base under line of credit facility.

+ References

No definition available.

+ Details

Name:	geos_LineOfCreditFacilityBorrowingBaseAsPercentOfEligibleForeignInsuredAccounts
Namespace Prefix:	geos_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of eligible inventory as borrowing base under line of credit facility.

+ References

No definition available.

+ Details

Name:	geos_LineOfCreditFacilityBorrowingBaseAsPercentOfEligibleInventory
Namespace Prefix:	geos_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of forced liquidation of certain inventory for borrowing base of line of credit facility.

+ References

No definition available.

+ Details

Name:	geos_LineOfCreditFacilityBorrowingBaseAsPercentOfForcedLiquidationValueOfCertainInventory
Namespace Prefix:	geos_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482949/835-30-55-8

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 470
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-6

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Indicates type of variable interest rate on debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 470
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477734/942-470-50-3

+ Details

Name:	us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration
Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(b))
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-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=geos_WoodforestNationalBankMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 9 - Long-term Debt (Details Textual) - USD ($) $ in Thousands	Jul. 26, 2023	Jun. 30, 2025	Sep. 30, 2024
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) [Member]
Line of Credit [Member] \| Woodforest National Bank [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 15,000
Line of Credit Facility, Borrowing Base as Percent of Certain Accounts Receivable	80.00%
Line of Credit Facility, Borrowing Base As Percent of Eligible Foreign Insured Accounts	90.00%
Line of Credit Facility, Borrowing Base as Percent of Eligible Inventory	25.00%
Line of Credit Facility, Borrowing Base as Percent of Forced Liquidation Value of Certain Inventory	50.00%
Debt Instrument, Basis Spread on Variable Rate	3.25%
Debt Instrument, Interest Rate, Effective Percentage		7.65%
Debt Instrument, Covenant, Minimum Consolidated Tangible Net Worth	$ 100,000
Debt Instrument, Covenant, Minimum Liquidity	$ 5,000
Long-Term Line of Credit		$ 0	$ 0
Line of Credit [Member] \| Woodforest National Bank [Member] \| Minimum [Member]
Current Ratio	2
Interest Coverage Ratio	1.5
Letter of Credit [Member] \| Woodforest National Bank [Member]
Line of Credit Facility, Current Borrowing Capacity		14,900
Long-Term Line of Credit		$ 100