Investment Holdings (Details) - Investments (Unaudited) (iShares S&P Commodity-Indexed Investing Pool LLC [Member], USD $)	Sep. 30, 2013
Investment Holdings (Details) - Investments (Unaudited) [Line Items]
	$ 1,251,930,274
United States Treasury Bills: 0.01% - 0.03% Due 10/31/13 [Member]
Investment Holdings (Details) - Investments (Unaudited) [Line Items]
United States Treasury bills, Face Amount	442,446,000
United States Treasury bills, Fair Value	442,437,828
	442,446,000
United States Treasury Bills:0.00 - 0.01% Due 12/5/13 [Member]
Investment Holdings (Details) - Investments (Unaudited) [Line Items]
United States Treasury bills, Face Amount	462,504,000
United States Treasury bills, Fair Value	462,500,212
	462,504,000
United States Treasury Bills: 0.01% Due 12/19/13 [Member]
Investment Holdings (Details) - Investments (Unaudited) [Line Items]
United States Treasury bills, Face Amount	346,996,000
United States Treasury bills, Fair Value	346,992,234
	$ 346,996,000

Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 14

-Paragraph Column E

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 13

-Paragraph Column C

-Article 12

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12C

-Paragraph Column C

-Article 12

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-12.Column C.3,4)

-URI http://asc.fasb.org/extlink&oid=6955306&loc=d3e611133-123010

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 4

-Subparagraph (SX 210.12-12C.Column C.7)

-URI http://asc.fasb.org/extlink&oid=6955306&loc=d3e611225-123010

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 6

-Subparagraph (SX 210.12-14.Column E.2,3)

-URI http://asc.fasb.org/extlink&oid=6955306&loc=d3e611322-123010

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 5

-Subparagraph (SX 210.12-13.Column C.6)

-URI http://asc.fasb.org/extlink&oid=6955306&loc=d3e611282-123010

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12

-Paragraph Column C

-Article 12

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12

-Paragraph 3, 4

-Article 12

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 14

-Paragraph 2, 3

-Article 12

Reference 11: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 13

-Paragraph 6

-Article 12

Reference 12: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12C

-Paragraph 7

-Article 12

+ Details

- Definition

For investments which are quantified by principal amount, the principle balance held at close of period.

+ References+ Details