Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Summary Of Significant Accounting Policies [Line Items]
Material inventory losses recognized	$ 0	$ 0	$ 0
Accumulated amortization of intangible asset	6,440,000	13,477,000
Impairment of long-lived assets	0
Goodwill impairment	0	$ 0	$ 0
Impairment losses on investment	$ 0
Expected dividend yield	0.00%	0.00%	0.00%
Prepaid Expenses and Other Current Assets [Member]
Summary Of Significant Accounting Policies [Line Items]
Grants recorded	$ 1,400,000
Other Non-current Assets [Member]
Summary Of Significant Accounting Policies [Line Items]
Grants recorded	2,000,000.0
IPR&D [Member]
Summary Of Significant Accounting Policies [Line Items]
Accumulated amortization of intangible asset	$ 0	$ 0

Summary of significant accounting policies.

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Carrying amount as of the balance sheet date of amounts due under the terms of governmental, corporate, or foundation grants.

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The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

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Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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