Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Disaggregation Of Revenue [Line Items]
Revenue		$ 505,227	$ 461,785	$ 962,948	$ 890,836
Recurring revenue
Disaggregation Of Revenue [Line Items]
Revenue	[1]	452,710	414,845	857,835	799,803
Perpetual license
Disaggregation Of Revenue [Line Items]
Revenue		9,540	6,922	18,008	15,385
Professional services
Disaggregation Of Revenue [Line Items]
Revenue		$ 42,977	$ 40,018	$ 87,105	$ 75,648

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