Summary of Company's Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenue	$ 19,247	$ 20,558	$ 33,891	$ 35,843
Income (loss) from operations	(5,222)	(11,060)	(14,827)	(22,371)
Operating Segments | Seismic
Segment Reporting Information [Line Items]
Revenue	11,287	13,944	19,326	23,350
Income (loss) from operations	(3,757)	(9,156)	(11,430)	(18,609)
Operating Segments | Non-Seismic
Segment Reporting Information [Line Items]
Revenue	7,826	6,468	14,280	12,204
Income (loss) from operations	1,384	1,052	2,413	2,104
Corporate
Segment Reporting Information [Line Items]
Revenue	134	146	285	289
Income (loss) from operations	$ (2,849)	$ (2,956)	$ (5,810)	$ (5,866)