Basis of Presentation and Consolidation and Recently Issued Accounting Standards (Notes)	9 Months Ended
Jun. 30, 2013
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; the sale of structured over-the-counter (“OTC”) products in a wide range of commodities; physical trading and hedging of precious 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 accounts, representing approximately 11,000 consolidated 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, 2012, 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, 2012 filed with the SEC. These condensed consolidated financial statements include the accounts of INTL FCStone Inc. and all other entities in which the Company has a controlling financial interest. All material intercompany transactions and balances have been eliminated in consolidation. The Company’s fiscal year end is September 30, and the fiscal quarters end on December 31, March 31, June 30 and September 30. Unless otherwise stated, all dates refer to 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. Recent Accounting Pronouncements On December 16, 2011, the Financial Accounting Standards Board (“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 on or 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 expects 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 its condensed consolidated financial statements. In July 2012, the FASB issued final guidance on indefinite-lived intangible assets impairment testing. Under the guidance, entities testing indefinite-lived intangibles for impairment have the option of first performing a qualitative assessment to determine whether it is more likely than not that an indefinite-lived intangible asset is impaired. If a company determines that it is more likely than not that the fair value of such an asset exceeds its carrying amount, it would not need to calculate the fair value of the asset in that year. However, if a company concludes otherwise, it must calculate the fair value of the asset, compare that value with its carrying amount and record an impairment charge, if any. The guidance does not revise the requirement to test indefinite-lived intangible assets annually for impairment. In addition, the guidance does not amend the requirement to test indefinite-lived intangible assets for impairment between annual tests if events or circumstances warrant, however, it does revise the examples of events and circumstances that an entity should consider. The guidance is effective for annual and interim impairment tests performed for fiscal years beginning after September 15, 2012. Early adoption is permitted. The Company adopted this guidance and it did not have a material impact on the Company’s condensed consolidated financial statements. In February 2013, the FASB issued Accounting Standards Update (“ASU”) No. 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income requiring new disclosures regarding reclassification adjustments from accumulated other comprehensive income (“AOCI”). ASU No. 2013-02 requires disclosure of amounts reclassified out of AOCI by component. In addition, the entity is required to present, either on the face of the statement where net income is presented or the notes, significant amounts reclassified out of AOCI by the respective line items of net income. The Company expects to adopt this guidance starting with the first quarter of fiscal year 2014. The adoption of this guidance is not expected to have a material impact on the Company’s 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; the sale of structured over-the-counter (“OTC”) products in a wide range of commodities; physical trading and hedging of precious 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 accounts, representing approximately 11,000 consolidated 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, 2012, 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, 2012 filed with the SEC.

These condensed consolidated financial statements include the accounts of INTL FCStone Inc. and all other entities in which the Company has a controlling financial interest. All material intercompany transactions and balances have been eliminated in consolidation.

The Company’s fiscal year end is September 30, and the fiscal quarters end on December 31, March 31, June 30 and September 30. Unless otherwise stated, all dates refer to 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.

Recent Accounting Pronouncements

On December 16, 2011, the Financial Accounting Standards Board (“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 on or 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 expects 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 its condensed consolidated financial statements.

In July 2012, the FASB issued final guidance on indefinite-lived intangible assets impairment testing. Under the guidance, entities testing indefinite-lived intangibles for impairment have the option of first performing a qualitative assessment to determine whether it is more likely than not that an indefinite-lived intangible asset is impaired. If a company determines that it is more likely than not that the fair value of such an asset exceeds its carrying amount, it would not need to calculate the fair value of the asset in that year. However, if a company concludes otherwise, it must calculate the fair value of the asset, compare that value with its carrying amount and record an impairment charge, if any. The guidance does not revise the requirement to test indefinite-lived intangible assets annually for impairment. In addition, the guidance does not amend the requirement to test indefinite-lived intangible assets for impairment between annual tests if events or circumstances warrant, however, it does revise the examples of events and circumstances that an entity should consider. The guidance is effective for annual and interim impairment tests performed for fiscal years beginning after September 15, 2012. Early adoption is permitted. The Company adopted this guidance and it did not have a material impact on the Company’s condensed consolidated financial statements.

In February 2013, the FASB issued Accounting Standards Update (“ASU”) No. 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income requiring new disclosures regarding reclassification adjustments from accumulated other comprehensive income (“AOCI”). ASU No. 2013-02 requires disclosure of amounts reclassified out of AOCI by component. In addition, the entity is required to present, either on the face of the statement where net income is presented or the notes, significant amounts reclassified out of AOCI by the respective line items of net income. The Company expects to adopt this guidance starting with the first quarter of fiscal year 2014. The adoption of this guidance is not expected to have a material impact on the Company’s condensed consolidated financial statements.