Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2015	Oct. 31, 2015	Mar. 31, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	GEOSPACE TECHNOLOGIES CORP
Entity Central Index Key	0001001115
Document Type	10-K
Document Period End Date	Sep. 30, 2015
Amendment Flag	false
Document Fiscal Year Focus	2015
Trading Symbol	GEOS
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--09-30
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 211
Entity Common Stock, Shares Outstanding		13,147,916