The Company - (Detail) - USD ($) $ in Thousands	6 Months Ended
Mar. 31, 2022	Sep. 30, 2021
Class of Warrant or Right [Line Items]
Accumulated deficit	$ 716,784	$ 610,553
Subsequent Public Offering
Class of Warrant or Right [Line Items]
Proceeds of underwritten public offering common stock	1,333,700
Proceeds from issuance of debt	$ 13,800

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