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Sponsor's Fee - Additional Information (Detail) (USD $)
 6 Months Ended
Apr. 30, 2014
Component Of Other Income And Expense [Line Items]  
Sponsor's fee accrues daily and paid monthly, annual nominal Rate 0.40%
Maximum [Member]
  
Component Of Other Income And Expense [Line Items]  
Legal fees and expenses assumed sponsor $ 100,000
Minimum [Member]
  
Component Of Other Income And Expense [Line Items]  
Legal fees and expenses not assumed by sponsor $ 100,000