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, 2018	Sep. 30, 2017
Number of Shares
Outstanding at the beginning of the period (in shares)	1,994
Granted (in shares)	217
Exercised (in shares)	(42)
Outstanding at the end of the period (in shares)	2,169	1,994
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 3.83
Granted (in dollars per share)	6.33
Exercised (in dollars per share)	1.69
Outstanding at the end of the period (in dollars per share)	$ 4.38	$ 3.83
Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term	5 years 10 months 15 days	6 years 4 months 24 days
Aggregate Intrinsic Value
Outstanding at the beginning of the period (in dollars)	$ 8,489
Outstanding at the end of the period (in dollars)		$ 8,489