Trade Accounts Receivable and Financing Receivables - Financing Receivables (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Sep. 30, 2019
Accounts Notes And Loans Receivable [Line Items]
Total financing receivables	$ 939	$ 3,472
Total unearned income	(5)	(55)
Total financing receivables, net of unearned income	934	3,417
Less current portion	(934)	(3,233)
Non-current financing receivables		184
Promissory Notes
Accounts Notes And Loans Receivable [Line Items]
Total financing receivables	281	780
Sales Type Lease
Accounts Notes And Loans Receivable [Line Items]
Total financing receivables	658	2,692
Total unearned income	$ (5)	$ (55)