XML 16 R45.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Inventories and major vendors - Additional Information (Details)
12 Months Ended
Oct. 31, 2019
Oct. 31, 2018
Vendor One    
Inventory [Line Items]    
Concentration risk, percentage 13.00%  
Vendor Two    
Inventory [Line Items]    
Concentration risk, percentage 19.00%  
Two Vendors [Member]    
Inventory [Line Items]    
Concentration risk, percentage   40.00%