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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Revenue Recognition - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
Revenue Recognition - Narrative (Details) - USD ($)	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Revenue recognized included in contract liability balance at the beginning of the period			$ 9,900,000	$ 7,900,000
Impairment losses recognized on contract costs			0	0
Selling and marketing
Disaggregation of Revenue [Line Items]
Contract costs included in selling and marketing expenses	$ 300,000	$ 300,000	700,000	$ 500,000
Other Current and Non-current Assets
Disaggregation of Revenue [Line Items]
Contract costs	$ 2,400,000		$ 2,400,000		$ 2,300,000