XML 116 R73.htm IDEA: XBRL DOCUMENT v3.21.4
Concentration of major customers and suppliers (Details)
12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2019
Total sales | Customer concentration risk | Major customer one      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 64.00% 63.00% 64.00%
Total sales | Customer concentration risk | Major customer two      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 14.00%    
Accounts receivable | Customer concentration risk | Major Customers      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage   94.00%  
Accounts receivable | Customer concentration risk | Major customer one      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 75.00%    
Accounts receivable | Customer concentration risk | Major customer two      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 18.00%    
Advances to suppliers | Supplier concentration risk | Major supplier one      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 32.00% 45.00%  
Advances to suppliers | Supplier concentration risk | Major supplier two      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 28.00% 44.00%  
Advances to suppliers | Supplier concentration risk | Major supplier three      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 24.00%    
Advances to suppliers | Supplier concentration risk | Major supplier four      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 16.00%    
Total purchases | Supplier concentration risk | Major supplier one      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 37.00% 39.00% 40.00%
Total purchases | Supplier concentration risk | Major supplier two      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 20.00% 41.00% 50.00%
Total purchases | Supplier concentration risk | Major supplier three      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 18.00%    
Total purchases | Supplier concentration risk | Major supplier four      
Major Customers And Suppliers [Line Items]      
Concentration risk, percentage 16.00%