Supporting Financial Information - Other Income (Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interest expense	$ (219)	$ (225)
Amortization of debt financing costs as interest expense	(65)	(60)
Change in fair value of derivative financial instruments	0	(79)
Other income (expense), net	6	0
Other income (expense) net	$ (278)	$ (364)