Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Details)

v3.8.0.1
Stockholders' Equity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended
Oct. 31, 2017
Oct. 31, 2016
Jul. 31, 2017
Dec. 31, 2014
Stockholders' Equity (Details) [Line Items]        
Common Stock, Par or Stated Value Per Share (in Dollars per share) $ 0.01   $ 0.01  
Percentage of Commission Payable on Equity Offering 3.00%      
Maximum Offering Price Under Sales Agreement $ 20,000     $ 20,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in Shares) 487,106      
Treasury Stock, Value, Acquired, Cost Method $ 815      
Excess Tax Benefit from Share-based Compensation, Financing Activities 0 $ 0    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options $ 1,000      
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition 14 months      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value $ 10 $ 8    
Officer [Member]        
Stockholders' Equity (Details) [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in Shares) 271,591      
Treasury Stock, Shares, Acquired (in Shares) 80,751      
Treasury Stock, Value, Acquired, Cost Method $ 815      
2011 Plan [Member]        
Stockholders' Equity (Details) [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in Shares) 349,600      
Common Stock [Member]        
Stockholders' Equity (Details) [Line Items]        
Authorized Common Stock That May Be Issued And Sold Under Sales Agreement $ 19,150      
Securities That May Be Sold Under The Agreement $ 150,000      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in Shares) 487,106      
Restricted Stock [Member]        
Stockholders' Equity (Details) [Line Items]        
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options $ 100      
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Outstanding Weighted Average Remaining Contractual Terms 25 months