Document and Entity Information	6 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2
Trading Symbol	GEOS
Entity Registrant Name	GEOSPACE TECHNOLOGIES CORP
Entity Central Index Key	0001001115
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		13,147,916