Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Disaggregation Of Revenue [Line Items]
Revenue		$ 2,097,053	$ 1,933,347	$ 1,807,159
Recurring revenue
Disaggregation Of Revenue [Line Items]
Revenue	[1]	1,907,918	1,736,188	1,616,328
Perpetual license
Disaggregation Of Revenue [Line Items]
Revenue		38,640	34,065	33,013
Professional services
Disaggregation Of Revenue [Line Items]
Professional services		$ 150,495	$ 163,094	$ 157,818

[1] Recurring revenue is comprised of on-premises subscription, perpetual support, SaaS, and cloud services revenue.