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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Revenue Recognition - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
Revenue Recognition - Narrative (Details) - USD ($)	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue recognized included in contract liability balance at the beginning of the period			$ 8,500,000	$ 5,600,000
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	$ 200,000	800,000	$ 600,000
Other Current and Non-current Assets
Disaggregation of Revenue [Line Items]
Contract costs	$ 2,300,000		$ 2,300,000		$ 1,500,000