Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Loss Contingencies [Line Items]
Assessed penalty				$ 127
Rent expense			$ 2,522	1,925
Class Action Suit in Superior Court of California, Orange County - Wage-and-hour law violations
Loss Contingencies [Line Items]
Estimated loss on class action lawsuit			11	385
Loss contingency, paid	$ 391		$ 95	$ 5
Scenario, Forecast [Member] | Class Action Suit in Superior Court of California, Orange County - Wage-and-hour law violations
Loss Contingencies [Line Items]
Loss contingency, paid		$ 32