Sponsor's Fee - Additional Information (Detail) (USD $)	6 Months Ended
	Apr. 30, 2015
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 per year assumed and paid by Sponsor	100,000
Minimum [Member]
Component Of Other Income And Expense [Line Items]
Legal fees and expenses not assumed by Sponsor	100,000