Quarterly report pursuant to Section 13 or 15(d)

Stock Incentive Plans - Additional Information (Detail)

v3.3.1.900
Stock Incentive Plans - Additional Information (Detail) - USD ($)
$ in Millions
1 Months Ended 9 Months Ended
Jul. 31, 2015
Oct. 31, 2015
Jul. 31, 2011
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 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%  
Share-based compensation arrangement by share-based payment award, options, vested in period, fair value   $ 2.4  
Share-based compensation arrangement by share-based payment award, options expensed period   2 years  
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.  
Minimum payroll deductions at base compensation under employee stock purchase plan 1.00%    
Maximum payroll deductions at base compensation under employee stock purchase plan 15.00%    
Offering period commence date Oct. 01, 2015    
Percentage of stock to be purchased under the plan 85.00%    
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