Quarterly report pursuant to Section 13 or 15(d)

Income Taxes - Additional Information (Detail)

v3.21.2
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
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