XML 67 R50.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Property, Plant and Equipment Estimated Useful Life (Details) | 12 Months Ended
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Sep. 30, 2017
Minimum |
Property Plant And Equipment [Line Items] |
Rental Equipment | 2 years
Maximum |
Property Plant And Equipment [Line Items] |
Rental Equipment | 5 years
Machinery and equipment | Minimum |
Property Plant And Equipment [Line Items] |
Property useful lives | 3 years
Machinery and equipment | Maximum |
Property Plant And Equipment [Line Items] |
Property useful lives | 15 years
Buildings and building improvements | Minimum |
Property Plant And Equipment [Line Items] |
Property useful lives | 10 years
Buildings and building improvements | Maximum |
Property Plant And Equipment [Line Items] |
Property useful lives | 50 years
Other | Minimum |
Property Plant And Equipment [Line Items] |
Property useful lives | 5 years
Other | Maximum |
Property Plant And Equipment [Line Items] |
Property useful lives | 10 years

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- Definition Rental equipment useful life. + References No definition available. + Details
Name: | geos_RentalEquipmentUsefulLife
Namespace Prefix: | geos_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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- 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_PropertyPlantAndEquipmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_MachineryAndEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_BuildingAndBuildingImprovementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_PropertyPlantAndEquipmentOtherTypesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |