Stock-based Compensation and Equity Grants - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 31, 2021	Sep. 30, 2020
Number of Shares
Options outstanding, September 30, 2020 (in shares)	2,129,000
Exercised (in shares)	(63,000)
Granted (in shares)	245,000
Cancelled (in shares)	(25,000)
Options outstanding, March 31, 2021 (in shares)	2,286,000	2,129,000
Weighted Average Exercise Price
Options outstanding, September 30, 2020 (in dollars per share)	$ 6.14
Exercised (in dollars per share)	3.62
Granted (in dollars per share)	10.04
Cancelled (in dollars per share)	6.28
Options outstanding, March 31, 2021 (in dollars per share)	$ 7.03	$ 6.14
Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term	7 years 6 months	7 years 4 months 24 days
Aggregate Intrinsic Value
Options outstanding at September 30, 2020	$ 6,593
Options outstanding at March 31, 2021	$ 11,407	$ 6,593