Stock-based Compensation, Equity Grants, and Warrants - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Jun. 30, 2017	Sep. 30, 2016
Number of Shares
Outstanding at the beginning of the period (in shares)	2,226
Granted (in shares)	400
Cancelled (in shares)	(397)
Outstanding at the end of the period (in shares)	2,229	2,226
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 1.43
Granted (in dollars per share)	5.94
Exercised (in dollars per share)	3.00
Outstanding at the end of the period (in dollars per share)	$ 3.66	$ 1.43
Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term	6 years 6 months	5 years 9 months 18 days
Aggregate Intrinsic Value
Outstanding at the beginning of the period (in dollars)	$ 7,581
Outstanding at the end of the period (in dollars)	$ 7,490	$ 7,581
Employee Stock Option
Aggregate Intrinsic Value
Average yield	2.46%
Contractual and expected life of grants	10 years
Price volatility	12.00%
Maximum | Employee Stock Option
Aggregate Intrinsic Value
Vair value share price (in dollars per share)	$ 0.93
Minimum | Employee Stock Option
Aggregate Intrinsic Value
Vair value share price (in dollars per share)	$ 1.47