Supporting Financial Information - Other Income (Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interest expense	$ (192)	$ (219)	$ (619)	$ (662)
Amortization of debt financing costs as interest expense	(70)	(70)	(202)	(194)
Change in fair value of derivative financial instruments	0	3	0	(49)
Other income (expense), net	0	17	20	17
Other income (expense) net	$ (262)	$ (269)	$ (801)	$ (888)