Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Revenue	$ 1,933,347	$ 1,807,159	$ 1,458,415
Total recurring revenue
Disaggregation Of Revenue [Line Items]
Revenue	1,736,188	1,616,328	1,281,949
Perpetual license
Disaggregation Of Revenue [Line Items]
Revenue	34,065	33,013	32,668
Professional services
Disaggregation Of Revenue [Line Items]
Professional services	$ 163,094	$ 157,818	$ 143,798