Reportable Segments - Narrative (Details) - Segment sales - Customer concentration
3 Months Ended
Oct. 31, 2020
Oct. 31, 2019
Two customers | Life Sciences    
Information as to operating segments    
Concentration risk within segment (as a percent) 48.30% 45.70%
Three customers | Dental    
Information as to operating segments    
Concentration risk within segment (as a percent) 41.20% 43.50%
Three customers | Dialysis    
Information as to operating segments    
Concentration risk within segment (as a percent) 50.80% 46.10%