Basis of Presentation and Consolidation and Recently Issued Accounting Standards (Notes)	9 Months Ended
Jun. 30, 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. Change in Precious Metals Accounting The Company engages in trading activities in a variety of physical commodities, including actively trading precious metals whereby the Company provides a full range of trading and hedging capabilities, including OTC products, to select producers, consumers, and investors. In the Company’s precious metals trading activities, it acts as a principal, committing its own capital to buy and sell precious metals on a spot and forward basis. On April 10, 2015 (the “transfer date”), the Company transitioned the portion of its precious metals business conducted through its unregulated domestic subsidiary, INTL Commodities Inc., to its United Kingdom based broker-dealer subsidiary, INTL FCStone Ltd. INTL FCStone Ltd. is regulated by the Financial Conduct Authority (“FCA”), the regulator of the financial services industry in the United Kingdom. Prior to the transfer, precious metals inventory held by INTL Commodities Inc. was valued at the lower of cost or market value, under the provisions of the Inventory Topic of the Accounting Standards Codification (“ASC”), using the weighted-average price and first-in first-out costing method. In anticipation of the transfer of the precious metals business, INTL Commodities Inc. liquidated all of its precious metals inventory as of the transfer date. Subsequent to the transfer, precious metals inventory held by INTL FCStone Ltd. is measured at fair value, with changes in fair value included as a component of ‘trading gains, net’ on the condensed consolidated income statement, in accordance with U.S. GAAP accounting requirements for broker-dealers. Precious metals inventory held by subsidiaries that are not broker-dealers continues to be valued at the lower of cost or market value. Prior to the transfer, INTL Commodities Inc. precious metals sales and costs of sales were recorded on a gross basis in accordance with the Revenue Recognition Topic of the ASC. Subsequent to the transfer, INTL FCStone Ltd. precious metals sales and cost of sales are presented on a net basis and included as a component of ‘trading gains, net’ on the condensed consolidated income statements, in accordance with U.S GAAP accounting requirements for broker-dealers. Precious metals sales and cost of sales for subsidiaries that are not broker-dealers continue to be recorded on a gross basis. The change has no effect on the Company’s operating revenues, income from continuing operations, or net income. Management has historically assessed the performance of the physical commodities businesses on an operating revenue basis, and continues to do so. Recent Accounting Pronouncements On May 28, 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. For public entities, the ASU is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early application is not permitted. The Company expects to adopt this guidance starting with the first quarter of fiscal year 2018. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its condensed consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting. 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. In July 2015, the FASB issued ASU No, 2015-11, "Inventory (Topic 330): Simplifying the Measurement of Inventory." Topic 330, Inventory, currently requires an entity to measure inventory at the lower of cost or market. Market could be replacement cost, net realizable value, or net realizable value less an approximately normal profit margin. The amendments do not apply to inventory that is measured using last-in, first-out (LIFO) or the retail inventory method. The amendments apply to all other inventory, which includes inventory that is measured using first-in, first-out (FIFO) or average cost. An entity should measure in scope inventory at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. Subsequent measurement is unchanged for inventory measured using LIFO or the retail inventory method. The amendments are effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. The amendments should be applied prospectively with earlier application permitted as of the beginning of an interim or annual reporting period. The guidance is applicable to the Company beginning October 1, 2017. 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.

Change in Precious Metals Accounting

The Company engages in trading activities in a variety of physical commodities, including actively trading precious metals whereby the Company provides a full range of trading and hedging capabilities, including OTC products, to select producers, consumers, and investors. In the Company’s precious metals trading activities, it acts as a principal, committing its own capital to buy and sell precious metals on a spot and forward basis.

On April 10, 2015 (the “transfer date”), the Company transitioned the portion of its precious metals business conducted through its unregulated domestic subsidiary, INTL Commodities Inc., to its United Kingdom based broker-dealer subsidiary, INTL FCStone Ltd. INTL FCStone Ltd. is regulated by the Financial Conduct Authority (“FCA”), the regulator of the financial services industry in the United Kingdom.

Prior to the transfer, precious metals inventory held by INTL Commodities Inc. was valued at the lower of cost or market value, under the provisions of the Inventory Topic of the Accounting Standards Codification (“ASC”), using the weighted-average price and first-in first-out costing method. In anticipation of the transfer of the precious metals business, INTL Commodities Inc. liquidated all of its precious metals inventory as of the transfer date. Subsequent to the transfer, precious metals inventory held by INTL FCStone Ltd. is measured at fair value, with changes in fair value included as a component of ‘trading gains, net’ on the condensed consolidated income statement, in accordance with U.S. GAAP accounting requirements for broker-dealers. Precious metals inventory held by subsidiaries that are not broker-dealers continues to be valued at the lower of cost or market value.

Prior to the transfer, INTL Commodities Inc. precious metals sales and costs of sales were recorded on a gross basis in accordance with the Revenue Recognition Topic of the ASC. Subsequent to the transfer, INTL FCStone Ltd. precious metals sales and cost of sales are presented on a net basis and included as a component of ‘trading gains, net’ on the condensed consolidated income statements, in accordance with U.S GAAP accounting requirements for broker-dealers. Precious metals sales and cost of sales for subsidiaries that are not broker-dealers continue to be recorded on a gross basis.

The change has no effect on the Company’s operating revenues, income from continuing operations, or net income. Management has historically assessed the performance of the physical commodities businesses on an operating revenue basis, and continues to do so.

Recent Accounting Pronouncements

On May 28, 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. For public entities, the ASU is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early application is not permitted. The Company expects to adopt this guidance starting with the first quarter of fiscal year 2018. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its condensed consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.

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.

In July 2015, the FASB issued ASU No, 2015-11, "Inventory (Topic 330): Simplifying the Measurement of Inventory." Topic 330, Inventory, currently requires an entity to measure inventory at the lower of cost or market. Market could be replacement cost, net realizable value, or net realizable value less an approximately normal profit margin. The amendments do not apply to inventory that is measured using last-in, first-out (LIFO) or the retail inventory method. The amendments apply to all other inventory, which includes inventory that is measured using first-in, first-out (FIFO) or average cost. An entity should measure in scope inventory at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. Subsequent measurement is unchanged for inventory measured using LIFO or the retail inventory method. The amendments are effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. The amendments should be applied prospectively with earlier application permitted as of the beginning of an interim or annual reporting period. The guidance is applicable to the Company beginning October 1, 2017. The adoption of this standard is not expected to have a material impact on the condensed consolidated financial statements.