Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Taxes [Line Items]
Foreign pretax earnings	$ 136,000	$ 62,100	$ 42,200
Current foreign tax expense related to foreign tax withholdings	9,500	7,500	6,400
Unrecognized tax benefits	12,980	$ 10,897	$ 7,994	$ 5,834
Unrecognized tax benefits that would impact the effective tax rate if recognized	12,300
Unrecognized tax benefits, accrued interest	$ 500
Effective income tax rate	21.00%
Unremitted earnings of foreign subsidiaries	$ 73,700
U.S. Federal
Income Taxes [Line Items]
Net operating loss carryforwards	5,400
Foreign NOL carryforwards
Income Taxes [Line Items]
Net operating loss carryforwards	600
California Franchise Tax Board | Research Tax Credit Carryforward
Income Taxes [Line Items]
Excess state research credit	16,000
Valuation allowance	$ 16,000