Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation (Details)

v3.21.2
Basis of Presentation (Details) - USD ($)
$ in Thousands
3 Months Ended
Oct. 31, 2021
Oct. 31, 2020
Basis of Presentation (Details) [Line Items]    
Fair value investments $ 29,810  
Cost of marketable securities 30,089  
Unrealized losses marketable securities $ 196  
Clinical Services [Member] | Third-party payers” and “Health Maintenance Organizations [Member]    
Basis of Presentation (Details) [Line Items]    
Concentration risk, percentage 32.00%  
Clinical Services [Member] | Revenue [Member] | Third-party payers” and “Health Maintenance Organizations [Member]    
Basis of Presentation (Details) [Line Items]    
Concentration risk, percentage 36.00% 33.00%