Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Details)

v3.19.2
Stockholders' Equity (Details) - USD ($)
 3 Months Ended 6 Months Ended 9 Months Ended 12 Months Ended
Jan. 05, 2018
Apr. 30, 2019
Apr. 30, 2018
Jan. 31, 2019
Apr. 30, 2019
Apr. 30, 2018
Jul. 31, 2018
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   $ 0.01    
Percentage of Commission Payable on Equity Offering         3.00%        
Maximum Offering Price Under Sales Agreement (in Dollars)   $ 20,000,000     $ 20,000,000     $ 20,000,000  
Excess Tax Benefit from Share-based Compensation, Financing Activities (in Dollars)         0 $ 0      
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount (in Dollars)   1,200,000     $ 1,200,000        
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition         17 months        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period         238,230        
Stock Issued During Period, Value, Employee Benefit Plan (in Dollars)   $ 832,000 $ 782,000   $ 832,000 782,000      
Performance Shares [Member]                  
Stockholders' Equity (Details) [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period         3 years        
Restricted Stock [Member]                  
Stockholders' Equity (Details) [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number   1,628     1,628        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value (in Dollars per share)   $ 6.00     $ 6.00        
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount (in Dollars)   $ 10,000     $ 10,000        
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Outstanding Weighted Average Remaining Contractual Terms         21 months        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period         0        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period         985        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value (in Dollars)         $ 4,000        
Stock Issued During Period, Value, Employee Benefit Plan (in Dollars)         $ 832,000 $ 782,000      
2011 Plan [Member]                  
Stockholders' Equity (Details) [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized 5,000,000               3,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized 2,000,000                
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant   1,222,000     1,222,000        
Common Stock [Member]                  
Stockholders' Equity (Details) [Line Items]                  
Authorized Common Stock That May Be Issued And Sold Under Sales Agreement (in Dollars)             $ 19,150,000    
Securities That May Be Sold Under The Agreement (in Dollars)             $ 150,000,000    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period     46,022   34,719 274,726      
Stock Issued During Period Shares Stock Options Exercised1         23,376        
Stock Issued During Period, Value, Employee Benefit Plan (in Dollars)   $ 3,000     $ 3,000        
Stock Issued During Period, Shares, Employee Benefit Plan   315,472 37,580   315,472 37,580      
Treasury Stock, Shares, Acquired           340,898      
Common Stock [Member] | Restricted Stock [Member]                  
Stockholders' Equity (Details) [Line Items]                  
Stock Issued During Period, Shares, Employee Benefit Plan         315,472 37,580      
Treasury Stock [Member]                  
Stockholders' Equity (Details) [Line Items]                  
Stock Issued During Period, Value, Employee Benefit Plan (in Dollars)     $ 1,014,000     $ 1,014,000      
Stock Issued During Period, Shares, Employee Benefit Plan     (106,911)     (106,911)      
Treasury Stock, Shares, Acquired           106,911      
Treasury Stock [Member] | Restricted Stock [Member]                  
Stockholders' Equity (Details) [Line Items]                  
Treasury Stock, Shares, Acquired           106,911      
Directors And Officers [Member]                  
Stockholders' Equity (Details) [Line Items]                  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period   203,511     203,511        
Stock Issued During Period Shares Stock Options Exercised1   23,376     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, Equity Instruments Other than Options, Grants in Period       80,500     32,000    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value (in Dollars)       $ 225,000     $ 141,000