Financing Receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Sep. 30, 2015
Accounts Notes And Loans Receivable [Line Items]
Total financing receivables	$ 12,887				$ 3,850	$ 3,520
Total unearned income	(617)
Total financing receivables, net of unearned income	12,270				3,850	3,520
Allowance for doubtful notes	(1,020)				(500)	0
Less current portion	3,055	$ 2,614	$ 1,890	$ 1,678	1,533	2,004
Non-current financing receivables	8,195	$ 588	$ 427	$ 1,385	1,817	1,516
Promissory Notes
Accounts Notes And Loans Receivable [Line Items]
Total financing receivables	4,306				$ 3,850	$ 3,520
Sales Type Lease
Accounts Notes And Loans Receivable [Line Items]
Total financing receivables	8,581
Total unearned income	(527)
Notes
Accounts Notes And Loans Receivable [Line Items]
Total unearned income	$ (90)