Income Taxes - Schedule of Valuation Allowance (Details) - Valuation Allowance of Deferred Tax Assets - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 8,439	$ 10,056	$ 903
Charged to cost and expenses	(260)	(1,934)	10,048
Charged to other accounts	588	317	(895)
Ending balance	$ 8,767	$ 8,439	$ 10,056