Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||||
|---|---|---|---|---|---|---|
Mar. 04, 2019 |
Jul. 31, 2021 |
Apr. 30, 2021 |
Jul. 31, 2020 |
Jul. 31, 2021 |
Jul. 31, 2020 |
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| Income Taxes Disclosure [Line Items] | ||||||
| Income tax benefit due to reversal of tax reserves | $ 200 | |||||
| Income tax benefit | $ 83 | $ 45 | 49 | $ 66 | ||
| 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 benefit | $ 100 | $ 100 | $ 100 | $ 100 | ||
| X | ||||||||||
- Definition Income taxes disclosure. No definition available.
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- 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) related to the reversal of tax reserves for uncertain tax positions. 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 YYYY-MM-DD format. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Details
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