Revenue from Contracts with Customers - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Sep. 30, 2021
Revenue from External Customer [Line Items]
Contract with customer, asset, expected to be transferred to receivables within the next 12 months and therefore	$ 13,400		$ 13,400
Contract with customer, asset, reclassified to receivable			6,900,000
Contract with customer, asset, increase in contract assets related to revenue recognized			11,900,000
Impairments of the contract cost asset	0	$ 0	0	$ 0
Deferred revenue, revenue recognized			443,500,000
Deferred revenue, additions			434,400,000
Short term and long term accounts receivable	696,900,000		696,900,000		$ 744,600,000
Refund liability	36,400,000		36,400,000		40,300,000
Allowance for doubtful accounts receivable	700,000		700,000		300,000
Amortization expense related to costs to obtain a contract with a customer	11,900,000	$ 11,700,000	36,200,000	$ 33,100,000
Deferred revenue	495,473,000		495,473,000		497,677,000
Revenue, remaining performance obligation, amount	1,412,400,000		1,412,400,000
Unrecorded
Revenue from External Customer [Line Items]
Revenue, remaining performance obligation, amount	916,900,000		916,900,000
Other Current Assets
Revenue from External Customer [Line Items]
Capitalized contract cost, net	39,700,000		39,700,000		40,200,000
Other Assets
Revenue from External Customer [Line Items]
Capitalized contract cost, net	$ 75,900,000		75,900,000		$ 81,100,000
Intland Software
Revenue from External Customer [Line Items]
Deferred revenue increased			$ 6,900,000