Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Tax [Line Items]
Valuation allowance	$ 67,726	$ 29,298	$ 18,259	$ 0
Description of effects of COVID-19	In response to the COVID-19 pandemic, the CARES Act was signed into law in March 2020. The CARES Act lifted certain deduction limitations originally imposed by the Tax Cuts and Jobs Act of 2017 (the “Tax Act”). Under the CARES Act, the Company was permitted to carryback net operating losses for up to five years for losses generated in fiscal 2018 through fiscal 2021. Net operating loss carrybacks were previously prohibited under the Tax Act. The CARES Act also eliminated the 80% of taxable income limitations by allowing corporate entities to fully utilize net operating loss carryforwards to offset taxable income in fiscal years 2018, 2019 or 2020. In addition, the CARES Act made qualified improvement property eligible for 15-year cost-recovery and 100% bonus depreciation. The enactment of the CARES Act resulted in a $28,721 and $8,581 income tax benefit related to a federal net operating loss carryback at the previously enacted 35% rate in the Company’s consolidated financial statements during the years ended September 30, 2021 and 2020, respectively.
Federal income tax expense (benefit), continuing operations	$ (433)	$ (28,583)	$ 1,149
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	21.00%
Liability for uncertainty in income taxes, current	$ 44	$ 105
Income tax receivable	$ 28,718	37,255
Percentage of annual tax deduction	80.00%
Net operating loss carryforward	$ 29,105	3,095
Earliest Tax Year [Member]
Income Tax [Line Items]
Open tax year	2018
Federal [Member]
Income Tax [Line Items]
Research and development tax credit carryforward	$ 16,870
Operating Loss Carryforwards	$ 109,363
Tax credit carry forward expiration year	2039
State [Member]
Income Tax [Line Items]
Research and development tax credit carryforward	$ 4,986
Operating Loss Carryforwards	$ 97,128
Net operating loss carryforward, state, expiration year	2040
Tax credit carry forward expiration year	2034
CARES Act [Member]
Income Tax [Line Items]
Federal income tax expense (benefit), continuing operations		$ 28,721	$ 8,581
Prior to CARES Act [Member]
Income Tax [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%	35.00%