Summary of Company's Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenue	$ 14,644	$ 15,285
Income (loss) from operations	(9,605)	(11,311)
Operating Segments | Seismic
Segment Reporting Information [Line Items]
Revenue	8,039	9,406
Income (loss) from operations	(7,673)	(9,453)
Operating Segments | Non-Seismic
Segment Reporting Information [Line Items]
Revenue	6,454	5,736
Income (loss) from operations	1,029	1,052
Corporate
Segment Reporting Information [Line Items]
Revenue	151	143
Income (loss) from operations	$ (2,961)	$ (2,910)