Statements of Income and Comprehensive Income (USD $)
3 Months Ended 12 Months Ended
Oct. 31, 2012
Jul. 31, 2012
Apr. 30, 2012
Jan. 31, 2012
Oct. 31, 2011
Jul. 31, 2011
Apr. 30, 2011
Jan. 31, 2011
Oct. 31, 2012
Oct. 31, 2011
Oct. 31, 2010
Income                      
Interest Income $ 4,700,414 $ 5,300,777 $ 7,242,218 $ 8,330,286 $ 9,146,127 $ 9,303,096 $ 7,722,984 $ 7,492,130 $ 25,573,695 $ 33,664,337 $ 24,143,782
Total Income 4,700,414 5,300,777 7,242,218 8,330,286 9,146,127 9,303,096 7,722,984 7,492,130 25,573,695 33,664,337 24,143,782
Expenses                      
Sponsor's fee (611,361) (617,609) (727,638) (824,938) (830,093) (853,445) (721,621) (693,829) (2,781,546) (3,098,988) (2,637,516)
Total Expenses (611,361) (617,609) (727,638) (824,938) (830,093) (853,445) (721,621) (693,829) (2,781,546) (3,098,988) (2,637,516)
Net Income 4,089,053 4,683,168 6,514,580 7,505,348 8,316,034 8,449,651 7,001,363 6,798,301 22,792,149 30,565,349 21,506,266
Other Comprehensive Income:                      
Currency translation adjustment (9,640) 204,596 (80,044) 306,138 245,733 232,004 462,088 28,066 421,050 967,891 479,267
Total Comprehensive Income $ 4,079,413 $ 4,887,764 $ 6,434,536 $ 7,811,486 $ 8,561,767 $ 8,681,655 $ 7,463,451 $ 6,826,367 $ 23,213,199 $ 31,533,240 $ 21,985,533
Basic and Diluted Earnings per Share $ 0.70 $ 0.78 $ 0.94 $ 0.94 $ 1.05 $ 1.07 $ 0.97 $ 0.98 $ 3.40 $ 4.07 $ 2.97
Weighted-average Shares Outstanding 5,820,109 6,033,152 6,966,111 7,993,478 7,933,152 7,893,478 7,220,225 6,959,783 6,701,776 7,503,973 7,253,014
Cash Dividends per Share $ 0.73 $ 0.83 $ 0.97 $ 0.99 $ 1.03 $ 1.06 $ 0.96 $ 0.95 $ 3.57 $ 4.01 $ 2.87