Additional lessor operating lease payments to be received.

No definition available.

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

- Definition

Leases.

+ References

No definition available.

+ Details

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Namespace Prefix:	geos_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Lessor Operating Lease Commenced Date

+ References

No definition available.

+ Details

Name:	geos_LessorOperatingLeaseCommencedDate
Namespace Prefix:	geos_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Operating Rental Revenue Property Lease

+ References

No definition available.

+ Details

Name:	geos_NumberOfOperatingRentalRevenuePropertyLease
Namespace Prefix:	geos_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of operating right-of use asset related to leased facility.

+ References

No definition available.

+ Details

Name:	geos_NumberOfOperatingRightOfUseAssetRelatedToLeasedFacility
Namespace Prefix:	geos_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Trade accounts receivables included lease receivables.

+ References

No definition available.

+ Details

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

- Definition

Amount of lease payments to be received by lessor for operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=124258985&loc=SL77919396-209981

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Term of lessor's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=124258985&loc=SL77919359-209981

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of operating lease income from lease payments and variable lease payments paid and payable to lessor. Includes, but is not limited to, variable lease payments not included in measurement of lease receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=124258985&loc=SL77919372-209981

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=123420820&loc=SL77919311-209978

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section 50
-Paragraph 6A
-URI http://asc.fasb.org/extlink&oid=124502072&loc=SL77927221-108306

+ Details

Name:	us-gaap_OperatingLeaseLeaseIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=geos_LeasedEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=geos_PropertyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
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- Details

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- Details

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Namespace Prefix:
Data Type:	na
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- Details

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Leases - Additional Information (Details)	3 Months Ended			6 Months Ended
Leases - Additional Information (Details)	Mar. 31, 2022 USD ($) OperatingRightOfUseAsset	Dec. 31, 2021	Mar. 31, 2021 USD ($)	Mar. 31, 2022 USD ($) PropertyLeases OperatingRightOfUseAsset	Mar. 31, 2021 USD ($)
Leases [Line Items]
Rental revenue	$ 3,135,000		$ 2,288,000	$ 8,094,000	$ 4,026,000
Future minimum lease payments to be received	636,000			$ 636,000
Number of operating rental revenue property lease \| PropertyLeases				2
Equipment
Leases [Line Items]
Trade accounts receivables included lease receivables	2,000,000.0			$ 2,000,000.0
Rental revenue	3,100,000		$ 2,300,000	8,000,000.0	$ 4,000,000.0
Future minimum lease payments to be received	8,300,000			8,300,000
Additional lessor operating lease payments to be received	3,000,000.0			3,000,000.0
Property
Leases [Line Items]
Rental revenue	$ 51,000			$ 81,000
Maximum \| Equipment
Leases [Line Items]
Lease term	6 months			6 months
Austin, Texas
Leases [Line Items]
Number of operating right-of use asset related to leased facility \| OperatingRightOfUseAsset	2			2
Calgary \| Property
Leases [Line Items]
Lease term		5 years
Lessor Operating Lease Commenced Date		2021-11
Bogota [Member] \| Property
Leases [Line Items]
Lease term		1 year
Lessor Operating Lease Commenced Date		2021-12