Basis of Presentation and Summary of Significant Accounting Policies - Deferred Profit (Details) $ in Thousands	Mar. 31, 2018 USD ($) systems equipment	Sep. 30, 2017 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of similarly configured systems and processes | systems	2
Number of similarly configured items of equipment | equipment	2
Deferred revenues	$ 7,793	$ 6,822
Deferred costs	2,708	2,741
Deferred profit	$ 5,085	$ 4,081