Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation Expense - Additional Information (Detail)

v3.20.1
Stock-Based Compensation Expense - Additional Information (Detail) - USD ($)
3 Months Ended
Apr. 30, 2020
Apr. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Options granted 0  
Stock Options [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized $ 1,400,000  
Share based compensation arrangement by share based payment award expected weighted average recognition period 2 years 1 month 6 days  
Restricted Stock Units and Deferred Stock Units [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized $ 800,000  
Share based compensation arrangement by share based payment award expected weighted average recognition period 1 year 1 month 6 days  
Performance Stock Units (PSUs) [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized $ 0  
2011 Compensation and Incentive Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation arrangement by share-based payment award, Description Option awards may be granted to employees at an exercise price per share of not less than 100% of the fair market value per common share on the date of the grant.  
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent 100.00%  
Share-based compensation arrangement by share based payment award, Option award expiration period 10 years  
2011 Compensation and Incentive Plan [Member] | Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation arrangement by Share-based payment award, vesting period 1 year  
2011 Compensation and Incentive Plan [Member] | Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation arrangement by Share-based payment award, vesting period 3 years  
2011 Compensation and Incentive Plan [Member] | Stock Compensation Plan    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation arrangement by share-based payment award, number of shares authorized 9,300,000  
Share-based compensation arrangement by share-based payment award, number of shares available for grant 2,862,095  
2011 Compensation and Incentive Plan [Member] | Deferred Stock Units [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation arrangement by Share-based payment award, vesting period 1 year  
2015 Employee Stock Purchase Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation arrangement by share-based payment award, number of shares available for grant 1,075,024  
Share-based compensation arrangement by share-based payment award, Description On each purchase date, eligible employees can purchase our stock at a price per share equal to 85% of the closing price of our common stock on the exercise date, but no less than par value.  
Discount percentage from market price of stock 85.00%  
Shares purchased under ESPP 5,702 7,819
2015 Employee Stock Purchase Plan [Member] | Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation arrangement by share-based payment award, number of shares authorized 1,150,000