Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation (Details)

v3.19.2
Basis of Presentation (Details) - USD ($)
3 Months Ended 9 Months Ended 12 Months Ended
Apr. 30, 2019
Apr. 30, 2018
Apr. 30, 2019
Apr. 30, 2018
Jul. 31, 2018
Basis of Presentation (Details) [Line Items]          
Minimum Estimated Material Impact On Financial Statements     $ 23,000,000    
Maximum Estimated Material Impact On Financial Statements     25,000,000    
Income Tax Expense (Benefit) $ 0 $ 0 $ 0 $ (1,097,000)  
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent       19.40%  
Effective Income Tax Rate Reconciliation, Tax Credit, Amount       $ 1,100,000  
Clinical Services [Member] | Revenue Benchmark [Member]          
Basis of Presentation (Details) [Line Items]          
Concentration Risk, Percentage     63.00% 72.00%  
Clinical Services [Member] | Revenue Benchmark [Member] | Third Party Payer And Health Maintenance Organizations [Member]          
Basis of Presentation (Details) [Line Items]          
Concentration Risk, Percentage 33.00% 40.00% 39.00% 39.00%  
Clinical Services [Member] | Accounts Receivable [Member] | Third Party Payer And Health Maintenance Organizations [Member]          
Basis of Presentation (Details) [Line Items]          
Concentration Risk, Percentage     14.00%   29.00%