Redeemable Capital Shares (Details) (USD $)
12 Months Ended
Oct. 31, 2012
Oct. 31, 2011
Oct. 31, 2010
Redeemable capital shares activity      
Opening balance, Shares 8,100,000 6,750,000 8,250,000
Opening balance, Amount $ 862,361,862 $ 663,665,283 $ 746,917,479
Shares issued, Shares 4,100,000 7,250,000 3,250,000
Shares issued, Amount 423,131,548 748,290,041 294,995,478
Stock redeemed, Shares (6,550,000) (5,900,000) (4,750,000)
Stock redeemed, Amount (676,167,642) (609,007,896) (431,197,241)
Adjustment to period Shares due to currency movement and other, Shares         
Adjustment to period Shares due to currency movement and other, Amount (22,242,814) 59,414,434 52,949,567
Ending balance, Shares 5,650,000 8,100,000 6,750,000
Ending balance, Amount $ 587,082,954 $ 862,361,862 $ 663,665,283