v3.22.2.2
Guarantees (Narrative) (Details) - USD ($)
3 Months Ended
Oct. 31, 2022
Oct. 31, 2021
Jul. 31, 2022
Guarantor Obligations      
Investment earnings $ 1,300,000 $ 1,200,000  
Unsecured revolving credit facility      
Guarantor Obligations      
Available credit facilities 63,000,000    
Multi-Currency Revolving Credit Facility      
Guarantor Obligations      
Available credit facilities 17,000,000    
Advanced Filtration Systems, Inc.      
Guarantor Obligations      
AFSI outstanding debt $ 67,700,000   $ 68,800,000