Acquisitions and Disposals (Notes)	12 Months Ended
Sep. 30, 2013
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	Acquisitions and Disposals Acquisitions in Fiscal 2013 The Company’s consolidated financial statements include the operating results of the acquired businesses from the dates of acquisition. The total amount of goodwill and intangible assets, in connection with these acquisitions, that is expected to be deductible for tax purposes is $5.6 million as of September 30, 2013. First American Capital and Trading Corp. On May 3, 2013, the Company reached an agreement in which First American Capital and Trading Corp. (“FACT”), has agreed to transfer its customer accounts to INTL FCStone Inc.’s broker-dealer subsidiary, INTL FCStone Securities Inc. Completion of this transaction is subject to certain conditions, including regulatory approval. FACT provides correspondent clearing services to institutional customers directly and through a global network of partners. FACT services a wide range of customers, including broker-dealers, investment advisors, and fund managers. The Company completed this transaction in the first quarter of fiscal 2014. Tradewire On December 12, 2012, the Company finalized an agreement to acquire certain institutional accounts from Tradewire Securities, LLC (“Tradewire Securities”), a Miami-based securities broker-dealer servicing customers throughout Latin America and a wholly owned subsidiary of Tradewire Group Ltd. These accounts were transferred to INTL FCStone Inc.’s broker-dealer subsidiary, INTL FCStone Securities. As part of the transaction, the Company hired more than 20 professional staff from Tradewire Securities’ securities broker-dealer business based in Miami, Florida. These professionals provide global brokerage services to a wide range of customers, including hedge funds, pension funds, broker-dealers and banks located in Latin America, the Caribbean, North America and Europe. The consideration to be paid for the acquisition of institutional accounts from Tradewire Securities consists of three annual contingent payments and a final contingent payment and the original estimated present value was estimated to be $5.6 million as of the acquisition date. The purchase price for the acquisition is not expected to be material to the consolidated financial statements. The present value of the estimated total purchase price, including contingent consideration, is $6.3 million (see Note 12). The Company obtained a third-party valuation of the intangible assets and contingent liabilities, and allocated the purchase costs among identified intangible assets with determinable useful lives and goodwill. The goodwill and intangible assets recognized in this transaction of $2.8 million and $2.8 million, respectively, were assigned to the Securities segment. Disposals in Fiscal 2013 Gletir Agente De Valores S.A. On February 28, 2013, the Company, through its subsidiaries INTL Netherlands B.V. and Gainvest Asset Management Ltda, entered into an agreement to sell all of its ownership interest in another subsidiary, Gletir Agente De Valores S.A. (“Gletir Agente”), to Gletir Financial Corp (the “Purchaser”). The Company sold the capital stock of Gletir Agente for $0.8 million. Gletir Agente had net assets of $0.6 million, which included $0.1 million of AOCI related to foreign currency translation, included in the consolidated balance sheet of the Company, at the time of the sale. The gain resulting from the sale price less the carrying amount of the net assets and the gain from the AOCI balance were recorded as components of other income on the consolidated income statement for the fiscal year ended ended September 30, 2013. Exit of Physical Base Metals Business During the quarter ended March 31, 2013, as a result of a change in management strategy in the Company’s base metals product line, the Company elected to pursue an exit of its physical base metals business through the sale and/or orderly liquidation of current open positions. During the fiscal year ended September 30, 2013, the Company completed a sale of a portion of the physical base metals open contract positions, and the liquidation of the majority of the remaining physical base metals open contract positions and inventory. The performance of the physical base metals activities resulted in pre-tax income of $1.4 million during the fiscal year ending September 30, 2013, including $1.9 million in contract termination costs incurred in the aforementioned sale. The Company believes the exit of the physical base metals business will be completed by the end of fiscal 2014. The physical base metals business is included in the C&RM Segment. The Company will continue to operate the portion of its base metals business related to non-physical assets, conducted primarily through the London Metals Exchange. The Company has considered the impact of the exit of the physical base metals business on the Company’s financial position, future operating results and liquidity, and believes the exit will not have a material negative impact to the consolidated financial statements, expected cash flows or liquidity of the Company. The Company evaluated the recoverability of long-lived and intangible assets as a result of this planned exit, noting no impairment charges. The Company believes any additional exit costs will not be material to the consolidated financial statements. Acquisitions in Fiscal 2012 During fiscal 2012, the Company acquired three businesses (Coffee Network, TRX Futures Limited and Aporte DTVM) and certain assets of the Metals Division of MF Global UK Limited, which were not considered significant on an individual or aggregate basis. The Company’s consolidated financial statements include the operating results of the acquired businesses from the dates of acquisition. These acquisitions resulted in the recognition of goodwill and intangible assets that is expected to be deductible for tax purposes of $0.7 million. Coffee Network In November 2011, the Company entered into an agreement to acquire 100% of the ownership interests in Coffee Network LLC (“Coffee Network”), an online news and analysis portal for the global coffee industry. Coffee Network provides up-to-the-minute news and in-depth analysis to subscribers around the globe from a network of correspondents and commodity analysts located in key coffee producing and consuming regions. These services provide a unique information solution to subscribers and a competitive advantage in today’s information-driven marketplace. The purchase price for the Coffee Network acquisition consists of an initial payment of $0.2 million, three additional annual contingent payments and a final contingent payment. See Note 12 for discussion of the contingent payments. The present value of the estimated total purchase price, including contingent consideration, is less than $0.3 million. The intangible assets recognized in this transaction were assigned to the C&RM segment. Purchase costs allocated to intangible assets with determinable useful lives are $0.2 million, which are being amortized over the remaining useful lives of the assets, and include customer relationships, websites and non-compete agreements (approximate two-year weighted-average useful life). MF Metals Team On November 25, 2011, INTL FCStone Ltd. Ltd, the Company’s wholly owned subsidiary in the United Kingdom (“UK”), arranged with the administrator of MF Global’s UK operations to acquire certain assets of the Metals Division of MF Global UK Limited (in special administration). As part of the arrangement, the Company received an assignment of customer accounts and customer account documentation. Additionally, as part of the transaction, the Company hired more than 50 professionals from MF Global’s metals trading business based in London. This business serves institutional investors and financial services firms in the Americas, Europe and the Asia-Pacific region. The Company has allocated equity capital to integrate these brokers and their customers into the Company’s operations, through a combination of increased regulatory capital to support the accounts of these customers and increased compensation and related personnel costs for the brokers. The amount of the required capital depends upon the activity in and balances of the customer accounts. The purchase price of the acquisition of certain assets from MF Global was $1.0 million. There was no contingent consideration associated with this transaction. The intangible assets recognized in this transaction were assigned to the C&RM segment. Purchase costs allocated to intangible assets with determinable useful lives are $0.5 million, which are being amortized over the remaining useful lives of the assets, and include customer relationships (approximate three-year weighted-average useful life). TRX Futures Limited On April 30, 2012, the Company’s wholly owned subsidiary in the UK, INTL Holding (UK) Limited, acquired 100% of the outstanding shares of TRX Futures Limited (“TRX”) from Neumann Gruppe GmbH. TRX is a London-based niche clearing firm for commercial coffee and cocoa customers, as well as energy and financial products. The purchase price was equal to the tangible net asset value of TRX, which was approximately $12.9 million. There are no additional payments remaining for this acquisition. The goodwill recognized in this transaction was assigned to the C&RM segment. Purchase costs allocated to goodwill of $0.3 million was calculated as the excess of the fair value of the consideration transferred over the fair value of the identified net assets acquired and liabilities assumed, and is expected to be deductible for tax purposes. Aporte DTVM In February 2012, the Company’s subsidiaries, INTL Participacoes LTDA and FCStone do Brasil, acquired 100% of the shares of Aporte DTVM. Following the acquisition, Aporte DTVM was renamed INTL FCStone DTVM Ltda. INTL FCStone DTVM is based in Brazil and is a broker-dealer regulated by the Central Bank of Brazil. The purchase price for the acquisition of the shares of Aporte DTVM was $1.5 million. There are no additional payments remaining for this acquisition. The goodwill recognized in this transaction was assigned to the C&RM segment. Purchase costs allocated to goodwill of $0.8 million was calculated as the excess of the fair value of the consideration transferred over the fair value of the identified net assets acquired and liabilities assumed, and is expected to be deductible for tax purposes. Acquisitions in Fiscal 2011 During fiscal 2011, the Company acquired two businesses, Hencorp Futures and Ambrian Commodities Limited, and certain assets from Hudson Capital Energy, LLC, which were not considered significant on an individual or aggregate basis. The Company’s consolidated financial statements include the operating results of the two businesses and certain purchased assets from the dates of acquisition. These acquisitions resulted in the recognition of goodwill and intangible assets that is expected to be deductible for tax purposes of $4.9 million. Hencorp Futures In October, 2010, the Company acquired all of the ownership interests in Hencorp Futures, the commodity futures operation of Miami-based Hencorp Group. Hencorp Futures specializes in the development and execution of risk-management programs designed to hedge price volatility in a number of widely traded commodities, including coffee, sugar, cocoa, grains and energy products. The transaction will enable the Company to round out its portfolio of commodity risk management services to include a more robust capability in soft commodities, especially coffee, where Hencorp Futures has established a substantial presence and reputation globally, and especially in Central and South America. The purchase price of the Hencorp Futures acquisition consisted of an initial payment of $2.3 million, two payments totaling $1.4 million and representing the adjusted tangible equity of Hencorp Futures as of September 30, 2011, payments of $0.3 million based on the adjusted pre-tax net earnings of Hencorp Futures for the fiscal year ended September 30, 2011 and 2012, respectively, two additional annual contingent payments and a final contingent payment. See Note 12 for discussion of the contingent payments. The present value of the estimated total purchase price, including contingent consideration, is $7.5 million. The Company obtained a third-party valuation of the intangible assets and contingent liabilities, and allocated the purchase costs among tangible assets, identified intangible assets with determinable useful lives, intangible assets with indefinite lives and goodwill. The intangible assets and goodwill recognized in this transaction were assigned to the C&RM segment. Purchase costs allocated to intangible assets with determinable useful lives are $1.7 million, which are being amortized over the remaining useful lives of the assets, and include customer relationships of $1.3 million (twenty-year weighted-average useful life) and non-compete agreements of $0.4 million (two-year weighted-average useful life). Purchase costs allocated to intangible assets with indefinite lives are $0.8 million, and relate to a trade name. See discussion in Note 10 for discussion of the impairment of the Hencorp Futures trade name during the fiscal year ended September 30, 2012. Goodwill of $2.1 million was calculated as the excess of the fair value of the consideration transferred over the fair value of the identified net assets acquired and liabilities assumed, and is expected to be deductible for tax purposes. During 2012, Hencorp Futures was reorganized as a division of FCStone, LLC. Certain Assets Purchased from Hudson Capital Energy, LLC In April 2011, the Company acquired certain assets from Hudson Capital Energy LLC (“HCEnergy”), a New York-based energy risk-management firm. The transaction enables the Company’s energy risk management services to include a more robust capability in crude oil and refined products. HCEnergy is a specialist in exchange cleared options, swaps and futures, and has grown its business to include hedging and trading professionals across the spectrum of global petroleum products. The purchase price of the acquisition of certain assets from HCEnergy consisted of the aggregate net asset value of certain commodity futures brokerage accounts and certain proprietary software, totaling $1.0 million. There was no contingent consideration associated with this transaction. The Company has made an allocation of the purchase costs among tangible assets. There were no intangible assets or goodwill recognized in this transaction. Ambrian Commodities Limited In August 2011, the Company’s wholly owned subsidiary in the United Kingdom, INTL Global Currencies Limited, acquired the issued share capital of Ambrian Commodities Limited (“Ambrian”), the London Metals Exchange brokerage subsidiary of Ambrian Capital Plc. Ambrian was subsequently renamed INTL FCStone Ltd. (“INTL FCStone Europe”). INTL FCStone Europe, a non-clearing LME member, specializes in the development and execution of risk-management programs designed to hedge price fluctuations in base metals for a wide variety of producers, manufacturers and fabricators. INTL FCStone Europe has a niche focus on smaller industrial clients, including lead recyclers, brass producers, zinc galvanizers, metal refineries and copper foil producers that use LME futures and options for hedging raw material costs or output prices. At closing, the Company paid $7.1 million, representing the net asset value of Ambrian less certain intercompany balances due to Ambrian from its affiliates. There was no contingent consideration associated with this transaction. The Company has allocated the purchase costs among tangible assets. There were no intangible assets or goodwill recognized in this transaction.

Acquisitions and Disposals

Acquisitions in Fiscal 2013

The Company’s consolidated financial statements include the operating results of the acquired businesses from the dates of acquisition. The total amount of goodwill and intangible assets, in connection with these acquisitions, that is expected to be deductible for tax purposes is $5.6 million as of September 30, 2013.

First American Capital and Trading Corp.

On May 3, 2013, the Company reached an agreement in which First American Capital and Trading Corp. (“FACT”), has agreed to transfer its customer accounts to INTL FCStone Inc.’s broker-dealer subsidiary, INTL FCStone Securities Inc. Completion of this transaction is subject to certain conditions, including regulatory approval. FACT provides correspondent clearing services to institutional customers directly and through a global network of partners. FACT services a wide range of customers, including broker-dealers, investment advisors, and fund managers. The Company completed this transaction in the first quarter of fiscal 2014.

Tradewire

On December 12, 2012, the Company finalized an agreement to acquire certain institutional accounts from Tradewire Securities, LLC (“Tradewire Securities”), a Miami-based securities broker-dealer servicing customers throughout Latin America and a wholly owned subsidiary of Tradewire Group Ltd. These accounts were transferred to INTL FCStone Inc.’s broker-dealer subsidiary, INTL FCStone Securities. As part of the transaction, the Company hired more than 20 professional staff from Tradewire Securities’ securities broker-dealer business based in Miami, Florida. These professionals provide global brokerage services to a wide range of customers, including hedge funds, pension funds, broker-dealers and banks located in Latin America, the Caribbean, North America and Europe.

The consideration to be paid for the acquisition of institutional accounts from Tradewire Securities consists of three annual contingent payments and a final contingent payment and the original estimated present value was estimated to be $5.6 million as of the acquisition date. The purchase price for the acquisition is not expected to be material to the consolidated financial statements. The present value of the estimated total purchase price, including contingent consideration, is $6.3 million (see Note 12). The Company obtained a third-party valuation of the intangible assets and contingent liabilities, and allocated the purchase costs among identified intangible assets with determinable useful lives and goodwill. The goodwill and intangible assets recognized in this transaction of $2.8 million and $2.8 million, respectively, were assigned to the Securities segment.

Disposals in Fiscal 2013

Gletir Agente De Valores S.A.

On February 28, 2013, the Company, through its subsidiaries INTL Netherlands B.V. and Gainvest Asset Management Ltda, entered into an agreement to sell all of its ownership interest in another subsidiary, Gletir Agente De Valores S.A. (“Gletir Agente”), to Gletir Financial Corp (the “Purchaser”). The Company sold the capital stock of Gletir Agente for $0.8 million. Gletir Agente had net assets of $0.6 million, which included $0.1 million of AOCI related to foreign currency translation, included in the consolidated balance sheet of the Company, at the time of the sale. The gain resulting from the sale price less the carrying amount of the net assets and the gain from the AOCI balance were recorded as components of other income on the consolidated income statement for the fiscal year ended ended September 30, 2013.

Exit of Physical Base Metals Business

During the quarter ended March 31, 2013, as a result of a change in management strategy in the Company’s base metals product line, the Company elected to pursue an exit of its physical base metals business through the sale and/or orderly liquidation of current open positions. During the fiscal year ended September 30, 2013, the Company completed a sale of a portion of the physical base metals open contract positions, and the liquidation of the majority of the remaining physical base metals open contract positions and inventory. The performance of the physical base metals activities resulted in pre-tax income of $1.4 million during the fiscal year ending September 30, 2013, including $1.9 million in contract termination costs incurred in the aforementioned sale. The Company believes the exit of the physical base metals business will be completed by the end of fiscal 2014. The physical base metals business is included in the C&RM Segment. The Company will continue to operate the portion of its base metals business related to non-physical assets, conducted primarily through the London Metals Exchange.

The Company has considered the impact of the exit of the physical base metals business on the Company’s financial position, future operating results and liquidity, and believes the exit will not have a material negative impact to the consolidated financial statements, expected cash flows or liquidity of the Company. The Company evaluated the recoverability of long-lived and intangible assets as a result of this planned exit, noting no impairment charges. The Company believes any additional exit costs will not be material to the consolidated financial statements.

Acquisitions in Fiscal 2012

During fiscal 2012, the Company acquired three businesses (Coffee Network, TRX Futures Limited and Aporte DTVM) and certain assets of the Metals Division of MF Global UK Limited, which were not considered significant on an individual or aggregate basis. The Company’s consolidated financial statements include the operating results of the acquired businesses from the dates of acquisition.

These acquisitions resulted in the recognition of goodwill and intangible assets that is expected to be deductible for tax purposes of $0.7 million.

Coffee Network

In November 2011, the Company entered into an agreement to acquire 100% of the ownership interests in Coffee Network LLC (“Coffee Network”), an online news and analysis portal for the global coffee industry. Coffee Network provides up-to-the-minute news and in-depth analysis to subscribers around the globe from a network of correspondents and commodity analysts located in key coffee producing and consuming regions. These services provide a unique information solution to subscribers and a competitive advantage in today’s information-driven marketplace.

The purchase price for the Coffee Network acquisition consists of an initial payment of $0.2 million, three additional annual contingent payments and a final contingent payment. See Note 12 for discussion of the contingent payments. The present value of the estimated total purchase price, including contingent consideration, is less than $0.3 million. The intangible assets recognized in this transaction were assigned to the C&RM segment. Purchase costs allocated to intangible assets with determinable useful lives are $0.2 million, which are being amortized over the remaining useful lives of the assets, and include customer relationships, websites and non-compete agreements (approximate two-year weighted-average useful life).

MF Metals Team

On November 25, 2011, INTL FCStone Ltd. Ltd, the Company’s wholly owned subsidiary in the United Kingdom (“UK”), arranged with the administrator of MF Global’s UK operations to acquire certain assets of the Metals Division of MF Global UK Limited (in special administration). As part of the arrangement, the Company received an assignment of customer accounts and customer account documentation. Additionally, as part of the transaction, the Company hired more than 50 professionals from MF Global’s metals trading business based in London. This business serves institutional investors and financial services firms in the Americas, Europe and the Asia-Pacific region. The Company has allocated equity capital to integrate these brokers and their customers into the Company’s operations, through a combination of increased regulatory capital to support the accounts of these customers and increased compensation and related personnel costs for the brokers. The amount of the required capital depends upon the activity in and balances of the customer accounts.

The purchase price of the acquisition of certain assets from MF Global was $1.0 million. There was no contingent consideration associated with this transaction. The intangible assets recognized in this transaction were assigned to the C&RM segment. Purchase costs allocated to intangible assets with determinable useful lives are $0.5 million, which are being amortized over the remaining useful lives of the assets, and include customer relationships (approximate three-year weighted-average useful life).

TRX Futures Limited

On April 30, 2012, the Company’s wholly owned subsidiary in the UK, INTL Holding (UK) Limited, acquired 100% of the outstanding shares of TRX Futures Limited (“TRX”) from Neumann Gruppe GmbH. TRX is a London-based niche clearing firm for commercial coffee and cocoa customers, as well as energy and financial products. The purchase price was equal to the tangible net asset value of TRX, which was approximately $12.9 million. There are no additional payments remaining for this acquisition. The goodwill recognized in this transaction was assigned to the C&RM segment. Purchase costs allocated to goodwill of $0.3 million was calculated as the excess of the fair value of the consideration transferred over the fair value of the identified net assets acquired and liabilities assumed, and is expected to be deductible for tax purposes.

Aporte DTVM

In February 2012, the Company’s subsidiaries, INTL Participacoes LTDA and FCStone do Brasil, acquired 100% of the shares of Aporte DTVM. Following the acquisition, Aporte DTVM was renamed INTL FCStone DTVM Ltda. INTL FCStone DTVM is based in Brazil and is a broker-dealer regulated by the Central Bank of Brazil. The purchase price for the acquisition of the shares of Aporte DTVM was $1.5 million. There are no additional payments remaining for this acquisition. The goodwill recognized in this transaction was assigned to the C&RM segment. Purchase costs allocated to goodwill of $0.8 million was calculated as the excess of the fair value of the consideration transferred over the fair value of the identified net assets acquired and liabilities assumed, and is expected to be deductible for tax purposes.

Acquisitions in Fiscal 2011

During fiscal 2011, the Company acquired two businesses, Hencorp Futures and Ambrian Commodities Limited, and certain assets from Hudson Capital Energy, LLC, which were not considered significant on an individual or aggregate basis. The Company’s consolidated financial statements include the operating results of the two businesses and certain purchased assets from the dates of acquisition.

These acquisitions resulted in the recognition of goodwill and intangible assets that is expected to be deductible for tax purposes of $4.9 million.

Hencorp Futures

In October, 2010, the Company acquired all of the ownership interests in Hencorp Futures, the commodity futures operation of Miami-based Hencorp Group. Hencorp Futures specializes in the development and execution of risk-management programs designed to hedge price volatility in a number of widely traded commodities, including coffee, sugar, cocoa, grains and energy products. The transaction will enable the Company to round out its portfolio of commodity risk management services to include a more robust capability in soft commodities, especially coffee, where Hencorp Futures has established a substantial presence and reputation globally, and especially in Central and South America.

The purchase price of the Hencorp Futures acquisition consisted of an initial payment of $2.3 million, two payments totaling $1.4 million and representing the adjusted tangible equity of Hencorp Futures as of September 30, 2011, payments of $0.3 million based on the adjusted pre-tax net earnings of Hencorp Futures for the fiscal year ended September 30, 2011 and 2012, respectively, two additional annual contingent payments and a final contingent payment. See Note 12 for discussion of the contingent payments. The present value of the estimated total purchase price, including contingent consideration, is $7.5 million.

The Company obtained a third-party valuation of the intangible assets and contingent liabilities, and allocated the purchase costs among tangible assets, identified intangible assets with determinable useful lives, intangible assets with indefinite lives and goodwill. The intangible assets and goodwill recognized in this transaction were assigned to the C&RM segment. Purchase costs allocated to intangible assets with determinable useful lives are $1.7 million, which are being amortized over the remaining useful lives of the assets, and include customer relationships of $1.3 million (twenty-year weighted-average useful life) and non-compete agreements of $0.4 million (two-year weighted-average useful life). Purchase costs allocated to intangible assets with indefinite lives are $0.8 million, and relate to a trade name. See discussion in Note 10 for discussion of the impairment of the Hencorp Futures trade name during the fiscal year ended September 30, 2012. Goodwill of $2.1 million was calculated as the excess of the fair value of the consideration transferred over the fair value of the identified net assets acquired and liabilities assumed, and is expected to be deductible for tax purposes. During 2012, Hencorp Futures was reorganized as a division of FCStone, LLC.

Certain Assets Purchased from Hudson Capital Energy, LLC

In April 2011, the Company acquired certain assets from Hudson Capital Energy LLC (“HCEnergy”), a New York-based energy risk-management firm. The transaction enables the Company’s energy risk management services to include a more robust capability in crude oil and refined products. HCEnergy is a specialist in exchange cleared options, swaps and futures, and has grown its business to include hedging and trading professionals across the spectrum of global petroleum products.

The purchase price of the acquisition of certain assets from HCEnergy consisted of the aggregate net asset value of certain commodity futures brokerage accounts and certain proprietary software, totaling $1.0 million. There was no contingent consideration associated with this transaction.

The Company has made an allocation of the purchase costs among tangible assets. There were no intangible assets or goodwill recognized in this transaction.

Ambrian Commodities Limited

In August 2011, the Company’s wholly owned subsidiary in the United Kingdom, INTL Global Currencies Limited, acquired the issued share capital of Ambrian Commodities Limited (“Ambrian”), the London Metals Exchange brokerage subsidiary of Ambrian Capital Plc. Ambrian was subsequently renamed INTL FCStone Ltd. (“INTL FCStone Europe”). INTL FCStone Europe, a non-clearing LME member, specializes in the development and execution of risk-management programs designed to hedge price fluctuations in base metals for a wide variety of producers, manufacturers and fabricators. INTL FCStone Europe has a niche focus on smaller industrial clients, including lead recyclers, brass producers, zinc galvanizers, metal refineries and copper foil producers that use LME futures and options for hedging raw material costs or output prices.

At closing, the Company paid $7.1 million, representing the net asset value of Ambrian less certain intercompany balances due to Ambrian from its affiliates. There was no contingent consideration associated with this transaction. The Company has allocated the purchase costs among tangible assets. There were no intangible assets or goodwill recognized in this transaction.