Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Additional Information (Detail)

v3.8.0.1
Stockholders' Equity - Additional Information (Detail) - USD ($)
1 Months Ended 12 Months Ended
Jul. 13, 2017
Apr. 06, 2016
Jun. 30, 2016
Jul. 31, 2015
Jan. 31, 2018
Jan. 31, 2017
Jan. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Preferred stock, shares authorized         5,000,000    
Preferred stock, shares issued         0    
Expected dividend yield         0.00% 0.00% 0.00%
Market based options granted         1,400,000 1,581,614 612,678
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized         $ 1,100,000    
Share-based compensation arrangement by share-based payment award, options, grants in period, weighted average grant date fair value         $ 1.34 $ 3.09 $ 2.75
Share based compensation arrangement by share based payment award estimated weighted average amortization period         2 years 3 months 18 days    
Aggregate intrinsic value for options outstanding         $ 700,000 $ 0 $ 100,000
Aggregate intrinsic value of vested shares and share options expected to vest         $ 700,000 0 $ 100,000
Employee service share-based compensation, cash received from exercise of stock options           $ 200,000  
Stock options exercised         0 0 28,740
CEO [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Market based options granted   600,000     800,000    
Chief Operating Officer [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Market based options granted     200,000        
Officer [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Share-based compensation arrangement by share-based payment award, options, vested in period, fair value         $ 2,100,000    
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized         $ 300,000    
Share-based compensation arrangement by share-based payment award, options, vested in period         1 year 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         $ 2,900,000    
Share based compensation arrangement by share based payment award estimated weighted average amortization period         1 year 6 months    
Compensation and Incentive Plan 2011 [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Share-based compensation arrangement by share-based payment award, number of additional shares authorized 4,000,000            
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    
Compensation and Incentive Plan 2011 [Member] | Minimum [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Share-based compensation arrangement by Share-based payment award, Option award vesting period         1 year    
Compensation and Incentive Plan 2011 [Member] | Maximum [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Share-based compensation arrangement by Share-based payment award, Option award vesting period         4 years    
Compensation and Incentive Plan 2011 [Member] | Stock Compensation 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         2,527,281    
Long Term Incentive Program [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Share-based compensation arrangement by Share-based payment award, Option award vesting period             3 years
Long Term Incentive Program [Member] | Performance Stock Units (PSUs) [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Number of stock units granted         232,500 307,963 301,192
Fair value of stock units granted         $ 3,700,000    
Fair value of stock units granted, remaining contractual term         3 years    
Long Term Incentive Program [Member] | Performance Stock Units (PSUs) [Member] | Minimum [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Percentage of common stock expected to be issued         0.00% 0.00% 0.00%
Long Term Incentive Program [Member] | Performance Stock Units (PSUs) [Member] | Maximum [Member]              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Percentage of common stock expected to be issued         150.00% 150.00% 150.00%
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, Description         On each purchase date, eligible employees will 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    
Maximum payroll deductions at base compensation under employee stock purchase plan       15.00%      
Minimum payroll deductions at base compensation under employee stock purchase plan       1.00%      
Offering period commence date       Oct. 01, 2015      
Percentage of stock to be purchased under the plan       85.00%      
Shares purchased under ESPP         24,467 17,956  
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