XML 109 R96.htm IDEA: XBRL DOCUMENT
v3.23.3

Schedule II - Valuation and Qualifying Accounts - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Sep. 30, 2023 | Sep. 30, 2022
Allowance For Doubtful Accounts On Accounts And Financing Receivables [Member] |  |
Balance at beginning of period | $ 591 | $ 428
Charged to costs and expenses, net of recoveries | (138) | 292
Charged to other assets | 0 | 0
(deductions) and additions | (328) | (129)
Balance at end of period | 125 | 591
SEC Schedule, 12-09, Reserve, Inventory [Member] |  |
Balance at beginning of period | 13,971 | 13,636
Charged to costs and expenses, net of recoveries | 2,229 | 3,222
Charged to other assets | 0 | 0
(deductions) and additions | (2,139) | (2,887)
Balance at end of period | $ 14,061 | $ 13,971

X
- Definition Amount of valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column B)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-4 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column E)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-4 + Details
Name: | us-gaap_ValuationAllowancesAndReservesBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column C)(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-4 + Details
Name: | us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase in valuation and qualifying accounts and reserves from charge to accounts other than cost and expense. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column C)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-4 + Details
Name: | us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of decrease in valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column D)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-4 + Details
Name: | us-gaap_ValuationAllowancesAndReservesDeductions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=geos_AllowanceForDoubtfulAccountsOnAccountsAndFinancingReceivablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_InventoryValuationReserveMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |