Financing Receivables (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017
Accounts Notes And Loans Receivable [Line Items]
Total financing receivables	$ 12,788	$ 12,887
Total unearned income	(395)	(617)
Total financing receivables, net of unearned income	12,393	12,270
Less allowance for doubtful promissory notes	(1,849)	(1,020)
Less current portion of financing receivables	(5,031)	(3,055)
Non-current financing receivables	5,513	8,195
Promissory Notes
Accounts Notes And Loans Receivable [Line Items]
Total financing receivables	6,661	4,306
Total unearned income	(95)	(90)
Sales Type Lease
Accounts Notes And Loans Receivable [Line Items]
Total financing receivables	6,127	8,581
Total unearned income	$ (300)	$ (527)