Note 1 - Organization	9 Months Ended
Sep. 30, 2013
iShares S&P Commodity-Indexed Trust [Member]
Note 1 - Organization [Line Items]
Business Description and Basis of Presentation [Text Block]	1 - Organization The iShares® S&P GSCI™ Commodity-Indexed Trust (the “Trust”) was organized as a Delaware statutory trust on July 7, 2006 and commenced operations on July 10, 2006. BlackRock Asset Management International Inc. (“BAMII”) is the “Sponsor” of the Trust and “Manager” of the iShares® S&P GSCI™ Commodity-Indexed Investing Pool LLC (the “Investing Pool”). BlackRock Institutional Trust Company, N.A. is the “Trustee” of the Trust. The Trust is governed by the Second Amended and Restated Trust Agreement, dated as of March 1, 2013 (the “Trust Agreement”), among the Sponsor, the Trustee and Wilmington Trust Company (the “Delaware Trustee”). The Trust issues units of beneficial interest (“Shares”) representing fractional undivided beneficial interests in its net assets. Substantially all of the net assets of the Trust consist of interests in the limited liability company interests of the Investing Pool. The Investing Pool holds long positions in exchange-traded index futures contracts, or "Index Futures," which may be of various expirations, on the S&P GSCI™ Excess Return Index (“S&P GSCI-ER”), together with cash, U.S. Treasury securities or short-term securities and similar securities that are eligible as margin deposits for the Investing Pool’s Index Future positions, referred to as “Collateral Assets.” The Index Futures held by the Investing Pool are listed on the Chicago Mercantile Exchange (the “CME”) and are called Commodity Excess Return Futures (“CERFs”). It is the objective of the Trust that the performance of the Shares will correspond generally, but will not necessarily be identical, to the performance of the S&P GSCI™ Total Return Index, which represents the return on a fully collateralized investment in the S&P CSCI-ER, before payment of the Trust’s and the Investing Pool’s expenses and liabilities. The Trust and the Investing Pool are each commodity pools, as defined in the Commodity Exchange Act (the "CEA") and the applicable regulations of the Commodity Futures Trading Commission (the “CFTC”) and are operated by BAMII, a commodity pool operator registered with the CFTC. BAMII is an indirect subsidiary of BlackRock, Inc. The accompanying unaudited financial statements were prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions for Form 10-Q and the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”). In the opinion of management, all material adjustments, consisting only of normal recurring adjustments considered necessary for a fair statement of the interim period financial statements have been made. Interim period results are not necessarily indicative of results for a full-year period. These financial statements and the notes thereto should be read in conjunction with the Trust’s financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2012, as filed with the SEC on February 28, 2013. The Trust is not an investment company registered under the Investment Company Act of 1940, as amended.
iShares S&P Commodity-Indexed Investing Pool LLC [Member]
Note 1 - Organization [Line Items]
Business Description and Basis of Presentation [Text Block]	1 - Organization The iShares® S&P GSCI™ Commodity-Indexed Investing Pool LLC (the “Investing Pool”) is a limited liability company organized under the laws of the State of Delaware on July 7, 2006 and commenced operations on July 10, 2006. BlackRock Asset Management International Inc. (the “Manager”) is responsible for the administration of the Investing Pool. The Investing Pool holds long positions in exchange-traded index futures contracts, or "Index Futures," which may be of various expirations, on the S&P GSCI™ Excess Return Index (“S&P GSCI-ER”). In order to support margin requirements applicable to its Index Future positions, the Investing Pool also holds “Collateral Assets,” which consist of cash, U.S. Treasury securities or other short-term securities and similar securities that are eligible as margin deposits for those Index Future positions. The Index Futures held by the Investing Pool are listed on the Chicago Mercantile Exchange (the “CME”) and are called Commodity Excess Return Futures (“CERFs”). It is the objective of the Investing Pool that its performance will correspond generally, but will not necessarily be identical, to the performance of the S&P GSCI™ Total Return Index (the “Index”) before payment of the Investing Pool’s expenses and liabilities. The Investing Pool is a commodity pool, as defined in the Commodity Exchange Act (the “CEA”) and the applicable regulations of the Commodity Futures Trading Commission (the “CFTC”) and is operated by the Manager, a commodity pool operator registered with the CFTC. The Manager is an indirect subsidiary of BlackRock, Inc. BlackRock Fund Advisors (the “Advisor”), an indirect subsidiary of BlackRock, Inc., serves as the commodity trading advisor of the Investing Pool and is registered with the CFTC. The Investing Pool is not an investment company registered under the Investment Company Act of 1940, as amended.

Note 1 - Organization

9 Months Ended

Sep. 30, 2013

iShares S&P Commodity-Indexed Trust [Member]

Business Description and Basis of Presentation [Text Block]

1 - Organization

The iShares® S&P GSCI™ Commodity-Indexed Trust (the “Trust”) was organized as a Delaware statutory trust on July 7, 2006 and commenced operations on July 10, 2006. BlackRock Asset Management International Inc. (“BAMII”) is the “Sponsor” of the Trust and “Manager” of the iShares® S&P GSCI™ Commodity-Indexed Investing Pool LLC (the “Investing Pool”). BlackRock Institutional Trust Company, N.A. is the “Trustee” of the Trust. The Trust is governed by the Second Amended and Restated Trust Agreement, dated as of March 1, 2013 (the “Trust Agreement”), among the Sponsor, the Trustee and Wilmington Trust Company (the “Delaware Trustee”). The Trust issues units of beneficial interest (“Shares”) representing fractional undivided beneficial interests in its net assets. Substantially all of the net assets of the Trust consist of interests in the limited liability company interests of the Investing Pool. The Investing Pool holds long positions in exchange-traded index futures contracts, or "Index Futures," which may be of various expirations, on the S&P GSCI™ Excess Return Index (“S&P GSCI-ER”), together with cash, U.S. Treasury securities or short-term securities and similar securities that are eligible as margin deposits for the Investing Pool’s Index Future positions, referred to as “Collateral Assets.” The Index Futures held by the Investing Pool are listed on the Chicago Mercantile Exchange (the “CME”) and are called Commodity Excess Return Futures (“CERFs”).

It is the objective of the Trust that the performance of the Shares will correspond generally, but will not necessarily be identical, to the performance of the S&P GSCI™ Total Return Index, which represents the return on a fully collateralized investment in the S&P CSCI-ER, before payment of the Trust’s and the Investing Pool’s expenses and liabilities.

The Trust and the Investing Pool are each commodity pools, as defined in the Commodity Exchange Act (the "CEA") and the applicable regulations of the Commodity Futures Trading Commission (the “CFTC”) and are operated by BAMII, a commodity pool operator registered with the CFTC. BAMII is an indirect subsidiary of BlackRock, Inc.

The accompanying unaudited financial statements were prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions for Form 10-Q and the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”). In the opinion of management, all material adjustments, consisting only of normal recurring adjustments considered necessary for a fair statement of the interim period financial statements have been made. Interim period results are not necessarily indicative of results for a full-year period. These financial statements and the notes thereto should be read in conjunction with the Trust’s financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2012, as filed with the SEC on February 28, 2013.

The Trust is not an investment company registered under the Investment Company Act of 1940, as amended.

iShares S&P Commodity-Indexed Investing Pool LLC [Member]

Note 1 - Organization [Line Items]

Business Description and Basis of Presentation [Text Block]

1 - Organization

The iShares® S&P GSCI™ Commodity-Indexed Investing Pool LLC (the “Investing Pool”) is a limited liability company organized under the laws of the State of Delaware on July 7, 2006 and commenced operations on July 10, 2006. BlackRock Asset Management International Inc. (the “Manager”) is responsible for the administration of the Investing Pool. The Investing Pool holds long positions in exchange-traded index futures contracts, or "Index Futures," which may be of various expirations, on the S&P GSCI™ Excess Return Index (“S&P GSCI-ER”). In order to support margin requirements applicable to its Index Future positions, the Investing Pool also holds “Collateral Assets,” which consist of cash, U.S. Treasury securities or other short-term securities and similar securities that are eligible as margin deposits for those Index Future positions. The Index Futures held by the Investing Pool are listed on the Chicago Mercantile Exchange (the “CME”) and are called Commodity Excess Return Futures (“CERFs”).

It is the objective of the Investing Pool that its performance will correspond generally, but will not necessarily be identical, to the performance of the S&P GSCI™ Total Return Index (the “Index”) before payment of the Investing Pool’s expenses and liabilities.

The Investing Pool is a commodity pool, as defined in the Commodity Exchange Act (the “CEA”) and the applicable regulations of the Commodity Futures Trading Commission (the “CFTC”) and is operated by the Manager, a commodity pool operator registered with the CFTC. The Manager is an indirect subsidiary of BlackRock, Inc. BlackRock Fund Advisors (the “Advisor”), an indirect subsidiary of BlackRock, Inc., serves as the commodity trading advisor of the Investing Pool and is registered with the CFTC.

The Investing Pool is not an investment company registered under the Investment Company Act of 1940, as amended.