Summary of Revenue from the Sale of Products and Services Under Contracts with Customers Excludes All Revenue Earned from Rental Contracts by Geographic Areas (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Disaggregation Of Revenue [Line Items]
Total revenue	$ 11,845	$ 13,910	$ 22,304	$ 27,184
Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue	11,845	13,910	22,304	27,184
Operating Segments | Asia
Disaggregation Of Revenue [Line Items]
Total revenue	1,510	1,253	3,068	2,259
Operating Segments | Canada
Disaggregation Of Revenue [Line Items]
Total revenue	342	345	630	710
Operating Segments | Europe
Disaggregation Of Revenue [Line Items]
Total revenue	1,170	917	2,085	4,336
Operating Segments | United States
Disaggregation Of Revenue [Line Items]
Total revenue	8,265	11,338	14,875	19,361
Operating Segments | Other
Disaggregation Of Revenue [Line Items]
Total revenue	$ 558	$ 57	$ 1,646	$ 518