Note 13 - Other Current Liabilities (Details Textual) $ in Millions	12 Months Ended
Sep. 30, 2024 USD ($)
Minimum Amount Per Claimant On Which Company Purchased Stop Loss	$ 0.2

Minimum amount per claimant on which company purchased stop loss.

No definition available.

Name:	geos_MinimumAmountPerClaimantOnWhichCompanyPurchasedStopLoss
Namespace Prefix:	geos_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration