Quarterly report pursuant to Section 13 or 15(d)

Revenue Recognition (Details)

v3.10.0.1
Revenue Recognition (Details) - USD ($)
$ in Thousands
3 Months Ended
Oct. 31, 2018
Oct. 31, 2017
Sales Revenue, Net [Member]    
Revenue Recognition (Details) [Line Items]    
Concentration Risk, Percentage 67.00% 73.00%
Third Party Payer And Health Maintenance Organizations [Member] | Minimum [Member]    
Revenue Recognition (Details) [Line Items]    
Billing Information Filing Deadline Period   60 days
Third Party Payer And Health Maintenance Organizations [Member] | Maximum [Member]    
Revenue Recognition (Details) [Line Items]    
Billing Information Filing Deadline Period   90 days
Government Payer Medicare [Member]    
Revenue Recognition (Details) [Line Items]    
Billing Information Filing Deadline Period   60 days
Patient self-pay [Member]    
Revenue Recognition (Details) [Line Items]    
Billing Period   210 days
Receivable Collection Period   180 days
Products Revenue And Royalty Income [Member]    
Revenue Recognition (Details) [Line Items]    
Claim Period For Return Of Goods   30 days
Royalty Income, Nonoperating (in Dollars) $ 0 $ 261
Products Revenue And Royalty Income [Member] | Minimum [Member]    
Revenue Recognition (Details) [Line Items]    
Receivable Collection Period   30 days
Products Revenue And Royalty Income [Member] | Maximum [Member]    
Revenue Recognition (Details) [Line Items]    
Receivable Collection Period   90 days