XML 40 R27.htm IDEA: XBRL DOCUMENT
v3.19.1

Inventories (Tables) | 6 Months Ended
--- | ---
Mar. 31, 2019
Inventory Disclosure [Abstract] |
Inventories | Inventories consist of the following (in thousands):
|  | March 31, 2019 |  |  | September 30, 2018 |
Finished goods |  | $ | 18,750 |  |  | $ | 18,802 |
Work in process |  |  | 3,745 |  |  |  | 7,926 |
Raw material |  |  | 58,570 |  |  |  | 54,290 |
Obsolescence reserve |  |  | (31,503 | ) |  |  | (30,551 | )
|  |  | 49,562 |  |  |  | 50,467 |
Less current portion |  |  | (15,525 | ) |  |  | (18,812 | )
Non-current portion |  | $ | 34,037 |  |  | $ | 31,655 |

X
- Definition Schedule of inventory current and noncurrent. + References No definition available. + Details
Name: | geos_ScheduleOfInventoryCurrentAndNoncurrentTableTextBlock
Namespace Prefix: | geos_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InventoryDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration