Investment Holdings (Details) - Open Futures Contracts (Unaudited) (Futures [Member], iShares S&P Commodity-Indexed Investing Pool LLC [Member], USD $)	9 Months Ended
	Sep. 30, 2013		Dec. 31, 2012
Futures [Member] | iShares S&P Commodity-Indexed Investing Pool LLC [Member]
Derivative [Line Items]
	27,054
	March 2014
	$ 1,273,997,209
	$ 74,864,742	[1]	$ 64,502,960	[1]

[1] Futures contracts are valued at unrealized appreciation (depreciation).