Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity (Details)

v3.19.3
Stockholders' Equity (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Jan. 05, 2018
Jul. 31, 2019
Jul. 31, 2018
Jul. 31, 2017
Dec. 31, 2014
Jan. 14, 2011
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)   238,230 635,624 141,876    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value   $ 159 $ 743 $ 10,530    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value   955 1,723 14,510    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value   $ 117 $ 6,014 $ 1,388    
Performance Shares [Member]            
Stockholders' Equity (Details) [Line Items]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   3 years        
Minimum [Member]            
Stockholders' Equity (Details) [Line Items]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   2 years 2 years 2 years    
Maximum [Member]            
Stockholders' Equity (Details) [Line Items]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   3 years 3 years 3 years    
2011 Plan [Member]            
Stockholders' Equity (Details) [Line Items]            
Share Based Compensation Arrangement by Share Based Payment Award Restricted Stock Units (in Shares)           3,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in Shares) 2,000,000          
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in Shares) 5,000,000 1,223,000        
2011 Plan [Member] | Restricted Stock And Restricted Stock Unit Awards [Member]            
Stockholders' Equity (Details) [Line Items]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period       4 years    
2011 Plan [Member] | Minimum [Member]            
Stockholders' Equity (Details) [Line Items]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   2 years        
2011 Plan [Member] | Maximum [Member]            
Stockholders' Equity (Details) [Line Items]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   4 years        
Common Stock [Member]            
Stockholders' Equity (Details) [Line Items]            
Authorized Common Stock that may be Issued and Sold Under Sales Agreement     $ 19,200      
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)   34,719 294,726 141,876    
Treasury Stock, Shares, Acquired (in Shares)     340,898      
Stock Issued During Period, Shares, Employee Benefit Plan (in Shares)   315,472 37,580 91,541    
Payments of Stock Issuance Costs   $ 832 $ 782 $ 724    
Common Stock [Member] | Restricted Stock [Member]            
Stockholders' Equity (Details) [Line Items]            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value   $ 4 $ 24 $ 44    
Treasury Stock [Member]            
Stockholders' Equity (Details) [Line Items]            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in Shares)     340,898      
Treasury Stock, Shares, Acquired (in Shares)     106,911      
Treasury Stock, Value     $ 1,014      
Stock Issued During Period, Shares, Employee Benefit Plan (in Shares)     (106,911)      
Stock Issued During Period, Shares, Treasury Stock Reissued (in Shares)     106,911      
Directors And Officers [Member]            
Stockholders' Equity (Details) [Line Items]            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in Shares)   203,511        
Stock Issued During Period Shares Stock Options Exercised1 (in Shares)   23,376        
Executive Officer [Member] | Performance Shares [Member]            
Stockholders' Equity (Details) [Line Items]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   3 years 3 years      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value   $ 225 $ 141