Basis of Presentation and Consolidation and Recently Issued Accounting Standards (Notes)	6 Months Ended
Mar. 31, 2015
Basis of Presentation and Consolidation [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 diversified, global financial services organization providing financial products and advisory and execution services to help clients access market liquidity, maximize profits and manage risk. 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 metals and select other commodities; trading of more than 150 foreign currencies; market-making in international equities; fixed income; 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 clients 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, 2014, 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, 2014 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, self-insurance liabilities, 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 In June 2014, the FASB issued ASU 2014-11, Transfers and Servicing: Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures, which changes the accounting for repurchase-to-maturity transactions to secured borrowing accounting. Additionally, for repurchase financing arrangements, the amendments of this ASU require separate accounting for a transfer of a financial asset executed contemporaneously with a repurchase agreement with the same counterparty, which will result in secured borrowing accounting for the repurchase agreement. For public entities, the ASU is effective for the first interim or annual period beginning after December 15, 2014. Earlier application is not permitted. The Company adopted this guidance starting with the second quarter of fiscal year 2015. The adoption of this guidance did not have a material impact on the Company’s condensed consolidated financial statements. In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements - Going Concern: Disclosures of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which requires management to evaluate whether there are conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued or are available to be issued. This ASU also requires management to disclose certain information depending on the results of the going concern evaluation. The provisions of this ASU are effective for annual periods ending after December 15, 2016, and for interim and annual periods thereafter. Early adoption is permitted. This amendment is applicable to the Company for the fiscal year ended September 30, 2017. The adoption of this standard is not expected to have a material impact on the condensed consolidated financial statements. In January 2015, the FASB issued ASU 2015-01, Income Statement - Extraordinary and Unusual Items: Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items, which eliminates from U.S. GAAP the concept of extraordinary items. The ASU retains and expands the existing presentation and disclosure guidance for items that are unusual in nature or occur infrequently to also include items that are both unusual in nature and infrequently occurring. The provisions of this ASU are effective for annual periods and interim periods within those annual periods beginning after December 15, 2015. Early adoption is permitted, provided that presentation applied to the beginning of the fiscal year of adoption. This amendment is applicable to the Company beginning October 1, 2016. The adoption of this standard is not expected to have a material impact on the condensed consolidated financial statements. In April 2015, the FASB issued ASU 2015-03, Interest- Imputation of Interest (Subtopic 835-03) - Simplifying the Presentation of Debt Issuance Costs which requires unamortized debt issuance costs to be presented as a reduction of the corresponding debt liability rather than a separate asset. Amortization of the costs is reported as interest expense. The provisions of this ASU are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is allowed for all entities for financial statements that have not been previously issued. Entities should apply the new guidance retrospectively to all prior periods. The guidance is applicable to the Company beginning October 1, 2016. The adoption of this standard is not expected to have a material impact on 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 diversified, global financial services organization providing financial products and advisory and execution services to help clients access market liquidity, maximize profits and manage risk. 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 metals and select other commodities; trading of more than 150 foreign currencies; market-making in international equities; fixed income; 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 clients 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, 2014, 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, 2014 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, self-insurance liabilities, 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

In June 2014, the FASB issued ASU 2014-11, Transfers and Servicing: Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures, which changes the accounting for repurchase-to-maturity transactions to secured borrowing accounting. Additionally, for repurchase financing arrangements, the amendments of this ASU require separate accounting for a transfer of a financial asset executed contemporaneously with a repurchase agreement with the same counterparty, which will result in secured borrowing accounting for the repurchase agreement. For public entities, the ASU is effective for the first interim or annual period beginning after December 15, 2014. Earlier application is not permitted. The Company adopted this guidance starting with the second quarter of fiscal year 2015. The adoption of this guidance did not have a material impact on the Company’s condensed consolidated financial statements.

In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements - Going Concern: Disclosures of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which requires management to evaluate whether there are conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued or are available to be issued. This ASU also requires management to disclose certain information depending on the results of the going concern evaluation. The provisions of this ASU are effective for annual periods ending after December 15, 2016, and for interim and annual periods thereafter. Early adoption is permitted. This amendment is applicable to the Company for the fiscal year ended September 30, 2017. The adoption of this standard is not expected to have a material impact on the condensed consolidated financial statements.

In January 2015, the FASB issued ASU 2015-01, Income Statement - Extraordinary and Unusual Items: Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items, which eliminates from U.S. GAAP the concept of extraordinary items. The ASU retains and expands the existing presentation and disclosure guidance for items that are unusual in nature or occur infrequently to also include items that are both unusual in nature and infrequently occurring. The provisions of this ASU are effective for annual periods and interim periods within those annual periods beginning after December 15, 2015. Early adoption is permitted, provided that presentation applied to the beginning of the fiscal year of adoption. This amendment is applicable to the Company beginning October 1, 2016. The adoption of this standard is not expected to have a material impact on the condensed consolidated financial statements.

In April 2015, the FASB issued ASU 2015-03, Interest- Imputation of Interest (Subtopic 835-03) - Simplifying the Presentation of Debt Issuance Costs which requires unamortized debt issuance costs to be presented as a reduction of the corresponding debt liability rather than a separate asset. Amortization of the costs is reported as interest expense. The provisions of this ASU are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is allowed for all entities for financial statements that have not been previously issued. Entities should apply the new guidance retrospectively to all prior periods. The guidance is applicable to the Company beginning October 1, 2016. The adoption of this standard is not expected to have a material impact on the condensed consolidated financial statements.