Equity Incentive Plan - Schedule of Classification of Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 115,149	$ 86,400	$ 82,939
Sales and marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	37,351	32,026	24,893
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	27,005	22,019	13,488
General and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	36,824	20,416	33,033
License | Cost of Sales
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	47	509	144
Support and cloud services | Cost of Sales
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	6,910	5,004	4,302
Professional services | Cost of Sales
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 7,012	$ 6,426	$ 7,079