Income Taxes - Schedule of Components of Deferred Income Tax Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016
Current deferred income taxes:
Gross assets	$ 3,978	$ 4,384
Gross liabilities and valuation allowance	(439)	(378)
Net current deferred income tax asset	3,539	4,006
Noncurrent deferred income taxes:
Gross assets	18,559	16,170
Gross liabilities and valuation allowance	(18,330)	(16,308)
Net noncurrent deferred income tax asset (liability)	229	(138)
Net deferred income tax asset	$ 3,768	$ 3,868