Basis of Presentation and Consolidation	6 Months Ended
Mar. 31, 2012
Basis of Presentation and Consolidation and Recently Issued Accounting Standards [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Basis of Presentation and Consolidation and Recently Issued Accounting Standards INTL FCStone Inc., a Delaware corporation, and its consolidated subsidiaries (collectively “INTL” or “the Company”), form a financial services group focused on domestic and select international markets. The Company’s services include comprehensive risk management advisory services for commercial customers; execution of listed futures and options on futures contracts on all major commodity exchanges; structured over-the-counter (“OTC”) products in a wide range of commodities; physical trading and hedging of precious and base metals and select other commodities; trading of more than 130 foreign currencies; market-making in international equities; debt origination and asset management. The Company provides these services to a diverse group of more than 20,000 customers located throughout the world, including producers, processors and end-users of nearly all widely-traded physical commodities to manage their risks and enhance margins; to commercial counterparties who are end-users of the firm’s products and services; to governmental and non-governmental organizations; and to commercial banks, brokers, institutional investors and major investment banks. Basis of Presentation and Consolidation The accompanying condensed consolidated balance sheet as of September 30, 2011, which has been derived from audited financial statements, and the unaudited interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC"). Certain information and note disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") have been condensed or omitted pursuant to those rules and regulations. The Company believes that the disclosures made are adequate to make the information presented not misleading. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of the condensed consolidated financial statements for the interim periods presented have been reflected as required by Rule 10-01 of Regulation S-X. Operating results for interim periods are not necessarily indicative of the results that may be expected for the full year. It is suggested that these interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and related notes contained in the Company’s Form 10-K for the fiscal year ended September 30, 2011 filed with the SEC. These condensed consolidated financial statements include the accounts of INTL FCStone Inc. and its subsidiaries. Intercompany transactions and balances have been eliminated in consolidation. In accordance with the Consolidation Topic of the Accounting Standards Codification ("ASC"), the Company consolidates any variable interest entities for which it is the primary beneficiary, as defined. The Company applies the equity method of accounting when the Company does not have a controlling interest in an entity, but exerts significant influence over the entity. Our fiscal year end is September 30, and our fiscal quarters end on December 31, March 31, June 30 and September 30. Unless otherwise stated, all dates refer to our fiscal years and fiscal interim periods. The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The most significant of these estimates and assumptions relate to fair value measurements for financial instruments and investments, revenue recognition, the provision for potential losses from bad debts, valuation of inventories, valuation of goodwill and intangible assets, incomes taxes and contingencies. Although these and other estimates and assumptions are based on the best available information, actual results could be materially different from these estimates. Reclassifications To conform to the current presentation of the information concerning the Company's operating segments, the Company has reclassified $0.9 million and $2.0 million, for the three and six months ended March 31, 2011, respectively, of costs not allocated to operating segments as non-variable direct segment costs, impacting reported net segment income, see Note 16. Recent Accounting Pronouncements In June 2011, the FASB issued new guidance on the presentation of comprehensive income. This guidance eliminates the current option to report OCI and its components in the statement of changes in equity. Under this guidance, an entity can elect to present items of net income and OCI in one continuous statement or in two separate, but consecutive, statements. In addition, the guidance requires entities to show the effects of items reclassified from OCI to net income on the face of the financial statements. This guidance is effective for fiscal years beginning after December 15, 2011 and interim and annual periods thereafter. Early adoption is permitted, but full retrospective application is required. This guidance is effective for the Company's fiscal year beginning October 1, 2012 and all interim periods within that fiscal year. In December 2011, the FASB issued guidance that deferred the portion of the original guidance that required a company to separately present within net income reclassification adjustments of items out of accumulated other comprehensive income. The deferral is intended to be temporary until the FASB has time to reconsider these changes. The other provisions of the guidance will become effective as originally planned by the FASB. The Company is expecting to adopt this guidance in the first quarter of fiscal year 2013. As the Company reports comprehensive income within its condensed consolidated statements of stockholders' equity, the adoption of this guidance will result in a change in the presentation of comprehensive income in the Company's condensed consolidated financial statements. On December 16, 2011, the FASB issued new guidance on the disclosures about offsetting assets and liabilities. While the FASB retained the existing offsetting models under U.S. GAAP, the new standard requires disclosures to allow investors to better compare and understand significant quantitative differences in financial statements prepared under U.S. GAAP. The new standard is effective for annual periods beginning after January 1, 2013, and interim periods within those annual periods. Retrospective application is required. This guidance is effective for the Company's fiscal year beginning October 1, 2013. The Company is expecting to adopt this guidance starting with the first quarter of fiscal year 2014. The adoption of this guidance is expected to change some of the Company's disclosures within the notes to the condensed consolidated financial statements.

Basis of Presentation and Consolidation and Recently Issued Accounting Standards

INTL FCStone Inc., a Delaware corporation, and its consolidated subsidiaries (collectively “INTL” or “the Company”), form a financial services group focused on domestic and select international markets. The Company’s services include comprehensive risk management advisory services for commercial customers; execution of listed futures and options on futures contracts on all major commodity exchanges; structured over-the-counter (“OTC”) products in a wide range of commodities; physical trading and hedging of precious and base metals and select other commodities; trading of more than 130 foreign currencies; market-making in international equities; debt origination and asset management.

The Company provides these services to a diverse group of more than 20,000 customers located throughout the world, including producers, processors and end-users of nearly all widely-traded physical commodities to manage their risks and enhance margins; to commercial counterparties who are end-users of the firm’s products and services; to governmental and non-governmental organizations; and to commercial banks, brokers, institutional investors and major investment banks.

Basis of Presentation and Consolidation

The accompanying condensed consolidated balance sheet as of September 30, 2011, which has been derived from audited financial statements, and the unaudited interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC"). Certain information and note disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") have been condensed or omitted pursuant to those rules and regulations. The Company believes that the disclosures made are adequate to make the information presented not misleading. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of the condensed consolidated financial statements for the interim periods presented have been reflected as required by Rule 10-01 of Regulation S-X.

Operating results for interim periods are not necessarily indicative of the results that may be expected for the full year. It is suggested that these interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and related notes contained in the Company’s Form 10-K for the fiscal year ended September 30, 2011 filed with the SEC.

These condensed consolidated financial statements include the accounts of INTL FCStone Inc. and its subsidiaries. Intercompany transactions and balances have been eliminated in consolidation. In accordance with the Consolidation Topic of the Accounting Standards Codification ("ASC"), the Company consolidates any variable interest entities for which it is the primary beneficiary, as defined.

The Company applies the equity method of accounting when the Company does not have a controlling interest in an entity, but exerts significant influence over the entity.

Our fiscal year end is September 30, and our fiscal quarters end on December 31, March 31, June 30 and September 30. Unless otherwise stated, all dates refer to our fiscal years and fiscal interim periods.

The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The most significant of these estimates and assumptions relate to fair value measurements for financial instruments and investments, revenue recognition, the provision for potential losses from bad debts, valuation of inventories, valuation of goodwill and intangible assets, incomes taxes and contingencies. Although these and other estimates and assumptions are based on the best available information, actual results could be materially different from these estimates.

Reclassifications

To conform to the current presentation of the information concerning the Company's operating segments, the Company has reclassified $0.9 million and $2.0 million, for the three and six months ended March 31, 2011, respectively, of costs not allocated to operating segments as non-variable direct segment costs, impacting reported net segment income, see Note 16.

Recent Accounting Pronouncements

In June 2011, the FASB issued new guidance on the presentation of comprehensive income. This guidance eliminates the current option to report OCI and its components in the statement of changes in equity. Under this guidance, an entity can elect to present items of net income and OCI in one continuous statement or in two separate, but consecutive, statements. In addition, the guidance requires entities to show the effects of items reclassified from OCI to net income on the face of the financial statements. This guidance is effective for fiscal years beginning after December 15, 2011 and interim and annual periods thereafter. Early adoption is permitted, but full retrospective application is required. This guidance is effective for the Company's fiscal year beginning October 1, 2012 and all interim periods within that fiscal year. In December 2011, the FASB issued guidance that deferred the portion of the original guidance that required a company to separately present within net income reclassification adjustments of items out of accumulated other comprehensive income. The deferral is intended to be temporary until the FASB has time to reconsider these changes. The other provisions of the guidance will become effective as originally planned by the FASB. The Company is expecting to adopt this guidance in the first quarter of fiscal year 2013. As the Company reports comprehensive income within its condensed consolidated statements of stockholders' equity, the adoption of this guidance will result in a change in the presentation of comprehensive income in the Company's condensed consolidated financial statements.

On December 16, 2011, the FASB issued new guidance on the disclosures about offsetting assets and liabilities. While the FASB retained the existing offsetting models under U.S. GAAP, the new standard requires disclosures to allow investors to better compare and understand significant quantitative differences in financial statements prepared under U.S. GAAP. The new standard is effective for annual periods beginning after January 1, 2013, and interim periods within those annual periods. Retrospective application is required. This guidance is effective for the Company's fiscal year beginning October 1, 2013. The Company is expecting to adopt this guidance starting with the first quarter of fiscal year 2014. The adoption of this guidance is expected to change some of the Company's disclosures within the notes to the condensed consolidated financial statements.