XML 28 R15.htm IDEA: XBRL DOCUMENT v2.4.0.6
Significant Accounting Policies (Narrative) (Details) (USD $)
3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Dec. 31, 2012
Significant Accounting Policies [Abstract]      
Annualized rate of Sponsors Fee 0.60%    
Sponsor Fees $ 821,098 $ 689,202  
Fees payable to the Sponsor $ 301,152   $ 254,522