Property and Equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Property Plant And Equipment [Abstract]
Computers, office equipment and furniture	$ 662	$ 662
Research equipment	23,763	20,654
Software	356	631
Leasehold improvements	26,676	25,238
Total gross fixed assets	51,457	47,185
Less: Accumulated depreciation and amortization	(17,727)	(16,304)
Property and equipment, net	$ 33,730	$ 30,881

Research equipment gross.

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Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated amortization of capitalized costs for computer software, including but not limited to, acquired and internally developed computer software.

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Amount before accumulated depreciation of equipment commonly used in offices and stores that have no permanent connection to the structure of a building or utilities. Examples include, but are not limited to, desks, chairs, tables, and bookcases.

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Amount before accumulated depreciation of additions or improvements to assets held under a lease arrangement.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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