Quarterly report pursuant to Section 13 or 15(d)

Stock Incentive Plans - Additional Information (Detail)

v2.4.0.8
Stock Incentive Plans - Additional Information (Detail) (USD $)
0 Months Ended 9 Months Ended 0 Months Ended
Oct. 20, 2014
Oct. 31, 2014
Oct. 31, 2013
Jul. 31, 2011
Compensation and Incentive Plan 2011 [Member]
Oct. 20, 2014
Compensation and Incentive Plan 2011 [Member]
CEO [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       5,300,000  
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, Option award vesting period   3 years      
Share-based compensation arrangement by share based payment award, Option award expiration period   10 years      
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent   100.00%      
Shares, granted         500,000
Share-based compensation arrangement by share-based payment award, options, vested in period, fair value $ 1,700,000        
Stock-based compensation expense $ 33,000 $ 2,579,000 $ 2,425,000