Note 9 - Investing in Index Futures (Details) (iShares S&P Commodity-Indexed Investing Pool LLC [Member], USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
iShares S&P Commodity-Indexed Investing Pool LLC [Member]
Note 9 - Investing in Index Futures (Details) [Line Items]
Average Month End Notional Amount Of Derivative Contracts	$ 1,140,268,847	$ 1,293,502,033