Income Taxes - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Operating Loss Carryforwards [Line Items]
Income Tax Holiday, Aggregate Dollar Amount	$ 8,500	$ 6,000	$ 8,200
Income Tax Holiday, Income Tax Benefits Per Share	$ 0.14	$ 0.10	$ 0.13
Deferred Tax Assets, Operating Loss Carryforwards	$ 42,849	$ 41,252
Deferred Tax Assets, Tax Credit Carryforwards	28,858	34,187
Valuation Allowance, Deferred Tax Asset, Change in Amount	5,700	7,800
Unrecognized Tax Benefits	66,840	70,814	$ 51,767	$ 42,287
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	43,200	39,200	34,300
Unrecognized Tax Benefits, Period Increase (Decrease)	(1,500)	1,400	$ (1,000)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	2,900	$ 4,400
Foreign [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carry-forwards, net	63,400
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	300
Deferred Tax Assets, Tax Credit Carryforwards	3,100
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carry-forwards, net	52,000
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	33,300
Deferred Tax Assets, Operating Loss Carryforwards	85,300
Deferred Tax Assets, Tax Credit Carryforwards	7,800
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carry-forwards, net	253,100
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	195,300
Deferred Tax Assets, Operating Loss Carryforwards	448,400
Deferred Tax Assets, Tax Credit Carryforwards	29,500
Deferred Tax Assets, Tax Credit Carryforwards, Subject to Expiration	$ 3,900