Income Taxes - Schedule of Valuation Allowance (Details) - Valuation Allowance of Deferred Tax Assets - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 9,597	$ 8,767	$ 8,439
Charged to cost and expenses	(209)	1,575	(260)
Charged to other accounts	(1,157)	(745)	588
Ending balance	$ 8,231	$ 9,597	$ 8,767