Investment Holdings (Details) - Investments (Unaudited) (Parentheticals) (iShares S&P Commodity-Indexed Investing Pool LLC [Member])	9 Months Ended
	Sep. 30, 2013
Investment Holdings (Details) - Investments (Unaudited) (Parentheticals) [Line Items]
Total United States Treasury bills, percentage	98.27%	[1]
United States Treasury Bills: 0.01% - 0.03% Due 10/31/13 [Member]
Investment Holdings (Details) - Investments (Unaudited) (Parentheticals) [Line Items]
United States Treasury bills, due date	Oct. 31, 2013
United States Treasury Bills: 0.01% - 0.03% Due 10/31/13 [Member] | Minimum [Member]
Investment Holdings (Details) - Investments (Unaudited) (Parentheticals) [Line Items]
United States Treasury bills, effective rate	0.01%
United States Treasury Bills: 0.01% - 0.03% Due 10/31/13 [Member] | Maximum [Member]
Investment Holdings (Details) - Investments (Unaudited) (Parentheticals) [Line Items]
United States Treasury bills, effective rate	0.03%
United States Treasury Bills:0.00 - 0.01% Due 12/5/13 [Member]
Investment Holdings (Details) - Investments (Unaudited) (Parentheticals) [Line Items]
United States Treasury bills, due date	Dec. 05, 2013
United States Treasury Bills:0.00 - 0.01% Due 12/5/13 [Member] | Minimum [Member]
Investment Holdings (Details) - Investments (Unaudited) (Parentheticals) [Line Items]
United States Treasury bills, effective rate	0.00%	[2]
United States Treasury Bills:0.00 - 0.01% Due 12/5/13 [Member] | Maximum [Member]
Investment Holdings (Details) - Investments (Unaudited) (Parentheticals) [Line Items]
United States Treasury bills, effective rate	0.01%
United States Treasury Bills: 0.01% Due 12/19/13 [Member]
Investment Holdings (Details) - Investments (Unaudited) (Parentheticals) [Line Items]
United States Treasury bills, effective rate	0.01%
United States Treasury bills, due date	Dec. 19, 2013

[1] Percentage is based on members' equity.

[2] Rounds to less than 0.01%