Income Taxes - Schedule of Provision for Income Taxes Differed from the Amount Computed by Applying Federal Statutory Rate (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Federal tax provision at statutory rate	$ (7,633)	$ (41,738)	$ 10,137
State tax, net of federal benefit	(890)	185	3,979
Foreign tax rate and other foreign related tax items	3,203	920	(15,626)
Uncertain tax positions	4,202	25	861
Stock-based compensation	4,734	(15,020)	1,629
Global intangible low-taxed income	7,464	(554)	554
Goodwill impairment		39,933
Change in valuation allowance	27,101	128,034	(225)
Executive compensation	991	885	3,761
Non-deductible expenditures	211	210	238
R&D credits	(588)	(805)	(2,932)
Intangible property transfers	(18,930)
Provision for income taxes	$ 19,865	$ 112,075	$ 2,376

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Income tax reconciliation uncertain tax positions.

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Amount of reported income tax expense from difference to expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations, attributable to global intangible low-taxed income (GILTI).

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Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to expense for award under share-based payment arrangement. Excludes expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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Amount of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to nondeductible expense for award under share-based payment arrangement. Includes, but is not limited to, expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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