XML 88 R75.htm IDEA: XBRL DOCUMENT
v3.21.2

Long-Term Debt - Additional Information (Details) |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Mar. 02, 2011 USD ($) | Nov. 30, 2019 USD ($) | Mar. 31, 2021 USD ($) | Sep. 30, 2021 USD ($) | Sep. 30, 2020 USD ($)
Prime Rate |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Marginal interest rate |  |  |  | 3.25% |
Fourth Amendment |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Unencumbered liquid asset value |  | $ 5,000,000 |  |  |
Minimum tangible net worth |  | 140,000,000 |  |  |
Fifth Amendment |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Unencumbered liquid asset value |  | 10,000,000 |  |  |
Minimum tangible net worth |  | $ 145,000,000 |  |  |
Fifth Amendment | Eligible Accounts |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Maximum amount of borrowing based upon assets | $ 10,000,000 |  |  |  |
Sixth Amendment | Eligible Inventory |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Maximum amount of borrowing based upon assets | $ 20,000,000 |  |  |  |
Frost Bank Credit Agreement |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Total long-term debt outstanding |  |  |  | $ 0 | $ 0
Frost Bank Credit Agreement | New Agreement |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Credit agreement date |  |  |  | Mar. 02, 2011 |
Frost Bank Credit Agreement | Second Amendment |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Credit agreement expiration date | 2020-04 |  |  |  |
Borrowing base as percentage of assets | 80.00% |  |  |  |
Frost Bank Credit Agreement | Third Amendment |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Credit agreement expiration date |  | 2022-04 |  |  |
Frost Bank Credit Agreement | Fourth Amendment |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Maximum amount of available borrowing |  |  | $ 30,000,000 |  |
Frost Bank Credit Agreement | Fifth Amendment |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Minimum tangible net worth |  |  | 145,000,000 |  |
Maximum amount of available borrowing |  |  | $ 20,000,000 |  |
Funded ratio debt to EBITDA |  |  | 1.50 |  |
Frost Bank Credit Agreement | Fifth Amendment | Eligible Accounts |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Maximum amount of borrowing based upon assets |  |  | $ 20,000,000 |  |
Borrowing base as percentage of assets | 50.00% |  |  |  |
Frost Bank Credit Agreement | Sixth Amendment |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Minimum tangible net worth |  |  | $ 132,000,000 |  |
Funded ratio debt to EBITDA |  |  | 1.00 |  |
Frost Bank Credit Agreement | Sixth Amendment | Eligible Inventory |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Maximum amount of borrowing based upon assets |  |  | $ 15,000,000 |  |
Borrowing base as percentage of assets | 25.00% |  |  |  |

X
- Definition Funded ratio debt to EBITDA. + References No definition available. + Details
Name: | geos_FundedRatioDebtToEBITDA
Namespace Prefix: | geos_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line of credit facility borrowing base as percent of assets. + References No definition available. + Details
Name: | geos_LineOfCreditFacilityBorrowingBaseAsPercentOfAssets
Namespace Prefix: | geos_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line of credit facility expiration date. + References No definition available. + Details
Name: | geos_LineOfCreditFacilityExpirationDate
Namespace Prefix: | geos_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum amount of line of credit facility borrowing based upon assets. + References No definition available. + Details
Name: | geos_MaximumAmountOfLineOfCreditFacilityBorrowingBasedUponAssets
Namespace Prefix: | geos_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Minimum tangible net worth. + References No definition available. + Details
Name: | geos_MinimumTangibleNetWorth
Namespace Prefix: | geos_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Unencumbered liquid asset value. + References No definition available. + Details
Name: | geos_UnencumberedLiquidAssetValue
Namespace Prefix: | geos_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- 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

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the credit facility first became available, in YYYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityInitiationDate1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- 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 Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The carrying value as of the balance sheet date of the noncurrent portion 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 -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=99376301&loc=d3e1336-112600 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 45 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=99376301&loc=d3e1314-112600 + Details
Name: | us-gaap_LongTermLineOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_PrimeRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=geos_FourthAmendmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=geos_FifthAmendmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_NotesReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=geos_SixthAmendmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_InventoriesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=geos_FrostBankCreditAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_SecuredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=geos_SecondAmendmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=geos_ThirdAmendmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |