Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands |
3 Months Ended | ||
|---|---|---|---|
Mar. 04, 2019 |
Apr. 30, 2021 |
Apr. 30, 2020 |
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| Income Taxes Disclosure [Line Items] | |||
| Income tax expense (benefit) | $ (34) | $ 21 | |
| Preferred shares purchase rights, declared date as dividend | Mar. 04, 2019 | ||
| Preferred shares purchase rights for each common stock | 1 | ||
| Preferred shares purchase rights, record date as dividend | Mar. 15, 2019 | ||
| Tax benefits preservation plan expiration date | Mar. 04, 2022 | ||
| Maximum [Member] | |||
| Income Taxes Disclosure [Line Items] | |||
| Income tax expense (benefit) | $ 100 | $ 100 | |
| X | ||||||||||
- Definition Income taxes disclosure. No definition available.
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| X | ||||||||||
- Definition Number of preferred share purchase rights as dividend. No definition available.
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| X | ||||||||||
- Definition Preferred share purchase rights as dividend payable date declared day month and year. No definition available.
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| X | ||||||||||
- Definition Preferred share purchase rights as dividend payable date of record day month and year. No definition available.
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| X | ||||||||||
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Expiration date of each operating loss carryforward included in operating loss carryforward, in CCYY-MM-DD format. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Details
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