Commitments and Contingencies (Notes)	9 Months Ended
Jun. 30, 2014
Commitments and Contingencies [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingencies Legal and Regulatory Proceedings Certain conditions may exist as of the date that the financial statements are issued, which may result in a loss to the Company but which will only be resolved when one or more future events occur or fail to occur. The Company assesses such contingent liabilities, and such assessment inherently involves an exercise of judgment. In assessing loss contingencies related to legal and regulatory proceedings that are pending against the Company or unasserted claims that may result in such proceedings, the Company’s legal counsel evaluates the perceived merits of any legal proceedings or unasserted claims as well as the perceived merits of the amount of relief sought or expected to be sought therein. If the assessment of a contingency indicates that it is probable that a material loss had been incurred at the date of the financial statements and the amount of the liability can be estimated, then the estimated liability would be accrued in the Company’s financial statements. If the assessment indicates that a potentially material loss contingency is not probable, but is reasonably possible, or is probable but cannot be estimated, then the nature of the contingent liability, together with an estimate of the range of possible loss if determinable and material, would be disclosed. Neither accrual nor disclosure is required for loss contingencies that are deemed remote. The Company accrues legal fees related to contingent liabilities as they are incurred. In addition to the matters discussed below, from time to time and in the ordinary course of business, the Company is involved in various legal actions and proceedings, including tort claims, contractual disputes, employment matters, workers’ compensation claims and collections. The Company carries insurance that provides protection against certain types of claims, up to the policy limits of the insurance. As of June 30, 2014 and September 30, 2013, the condensed consolidated balance sheets include loss contingency accruals recorded prior to September 30, 2013 which are not material, individually or in the aggregate, to the Company’s financial position or liquidity. In the opinion of management, possible exposure from loss contingencies in excess of the amounts accrued, and in addition to the possible losses discussed below, is not likely to be material to the Company’s earnings, financial position or liquidity. The following is a summary of significant legal matters involving the Company. Securities Litigation and Regulatory Proceedings On January 13, 2014, a purported class action was filed in the United States District Court for the Southern District of New York against the Company and certain of its officers and directors. The complaint alleges violations of federal securities laws, and claims that the Company has issued false and misleading information concerning the Company’s business and prospects. The action seeks unspecified damages on behalf of persons who purchased the Company’s shares between February 17, 2010 and December 16, 2013. During March 2014, three motions for appointment as lead plaintiff were filed; two were subsequently withdrawn, leaving a single unopposed bid for lead plaintiff appointment, an appointment that was approved by the court on April 29, 2014. The lead plaintiff’s amended complaint was filed on June 13, 2014. The Company’s motion to dismiss the complaint was filed on July 28, 2014. The Company has not determined that losses related to this matter are probable. Because the matter is in the early stages of litigation and no discovery has been commenced, together with the inherent difficulty of predicting the outcome of litigation generally, the Company does not have sufficient information to determine the amount or range of reasonably possible loss with respect to these matters. The Company believes the case is without merit and intends to defend itself vigorously. The Company’s Directors’ and Officers’ insurance policy is expected to cover any liability and litigation costs in excess of the $0.5 million policy retention amount. Sentinel Litigation The Company’s subsidiary, FCStone, LLC, had a portion of its excess segregated funds invested with Sentinel Management Group Inc. (“Sentinel”), a registered FCM and an Illinois-based money manager that provided cash management services to other FCMs. In August 2007, Sentinel halted redemptions to customers and sold certain of the assets it managed to an unaffiliated third party at a significant discount. On August 17, 2007, subsequent to Sentinel’s sale of certain assets, Sentinel filed for bankruptcy protection and $15.5 million of FCStone, LLC’s $21.9 million in invested funds were returned to it. In August 2008, the bankruptcy trustee of Sentinel filed adversary proceedings against FCStone, LLC, and a number of other FCMs in the Bankruptcy Court for the Northern District of Illinois. The case was subsequently reassigned to the United States District Court, for the Northern District of Illinois. In the complaint, the trustee sought avoidance of alleged transfers or withdrawals of funds received by FCStone, LLC and other FCMs within 90 days prior to the filing of the Sentinel bankruptcy petition, as well as avoidance of post-petition distributions and disallowance of the proof of claim filed by FCStone, LLC. The trustee sought recovery of pre- and post-petition transfers totaling approximately $15.5 million. In April 2009, the trustee filed an amended complaint adding a claim for unjust enrichment. FCStone, LLC answered the complaints and all parties entered into the discovery phase of the litigation. In January 2011, the trustee filed a motion for summary judgment on various counts in the adversary proceedings filed in August 2008 against FCStone, LLC and a number of other FCMs. In January 2012, FCStone, LLC filed a motion for summary judgment in its favor with respect to the transfer of approximately $1.1 million to its customer segregated account on August 17, 2007, pursuant to the “safe harbor” provisions of Section 546(e) of the U.S. Bankruptcy Code. In April 2012, FCStone, LLC filed a motion to dismiss a portion of the trustee’s claims set forth in its amended complaint. The trial of this matter took place, as a test case, during October 2012. The trial court entered a judgment against FCStone, LLC on January 4, 2013. On January 17, 2013, the trial court entered an agreed order, staying execution and enforcement, pending an appeal of the judgment. By agreement, FCStone, LLC was required to post an appeal cash deposit of $8.0 million with the court, which was deposited on January 18, 2013. The oral arguments in the appeal were heard on December 10, 2013. On March 19, 2014 the appeal court ruled in favor of FCStone, LLC. On April 16, 2014, the trustee filed a petition for rehearing of the appeal. On May 19, 2014, the U.S. Court of Appeals for the Seventh Circuit denied the petition. The trustee has until August 18, 2014 to file a writ for certiorari with the U.S. Supreme Court. The Company has not determined that losses related to this matter are probable. The Company believes that if the appellate decision in favor of FCStone, LLC is reversed, the resulting pre-tax loss to FCStone, LLC would be in the range of $4 million to $6 million. Contractual Commitments Contingent Liabilities - Acquisitions Under the terms of the purchase agreements related to the acquisitions listed below, the Company has obligations to pay additional consideration if specific conditions and earnings targets are met. In accordance with the Business Combinations Topic of the ASC, the fair value of the additional consideration is recognized as a contingent liability as of the acquisition date. The contingent liability for these estimated additional purchase price considerations of $8.0 million and $9.6 million are included in ‘accounts payable and other accrued liabilities’ in the condensed consolidated balance sheets as of June 30, 2014 and September 30, 2013. The acquisition date fair value of additional consideration is remeasured to its fair value each reporting period, with changes in fair value recorded in current earnings. The change in fair value during the nine months ended June 30, 2014 and 2013 were increases of $0.1 million and $1.6 million, respectively, and are included in ‘other’ in the consolidated income statements. The Company has a contingent liability relating to the April 2014 acquisition of Forward Insight Commodities LLC, which may result in the payment of additional purchase price consideration. The contingent liability recorded represents the fair value of the expected consideration to be paid, based on the forecasted adjusted pre-tax net earnings during the twelve-month period following the closing of the acquisition. The present value of the estimated total purchase price, including contingent consideration, is $0.5 million as of June 30, 2014, which remains outstanding and is included in ‘accounts payable and other accrued liabilities’ in the consolidated balance sheet. The Company has a contingent liability relating to the December 2012 acquisition of the accounts of Tradewire Securities, LLC, which may result in the payment of additional purchase price consideration. The contingent liability recorded represents the fair value of the expected consideration to be paid, based on the forecasted adjusted pre-tax net earnings during three annual periods and a six month period, after the third annual period, following the closing of the acquisition, for a total of four payments, with a discount rate being applied to those future payments. The present value of the estimated total purchase price, including contingent consideration, is $6.3 million as of June 30, 2014, of which $4.8 million remains outstanding and is included in ‘accounts payable and other accrued liabilities’ in the consolidated balance sheet. The Company has a contingent liability relating to the November 2011 acquisition of Coffee Network, LLC, subsequently reorganized as a division of FCStone, LLC, which may result in the payment of additional purchase price consideration. The contingent liability recorded represents the fair value of the expected consideration to be paid, based on the forecasted adjusted pre-tax net earnings during the three annual periods following the closing of the acquisition plus a final contingent payment. The present value of the estimated total purchase price, including contingent consideration, is less than $0.1 million as of June 30, 2014, which has not been paid and is included in ‘accounts payable and other liabilities’ in the condensed consolidated balance sheet. The Company has a contingent liability relating to the October 2010 acquisition of Hencorp Becstone Futures, L.C., subsequently reorganized as a division of FCStone, LLC, which may result in the payment of additional purchase price consideration. The contingent liability recorded represents the fair value of the expected consideration to be paid, based on the forecasted adjusted pre-tax net earnings during the fourth fiscal year following the closing of the acquisition plus an additional final estimated contingent payment and a discount rate being applied to the future payments. The present value of the estimated total purchase price, including contingent consideration, is $7.5 million as of June 30, 2014, of which $2.6 million has not been paid and is included in ‘accounts payable and other liabilities’ in the condensed consolidated balance sheet. Exchange Member Guarantees The Company is a member of various exchanges that trade and clear futures and option contracts. Associated with its memberships, the Company may be required to pay a proportionate share of the financial obligations of another member who may default on its obligations to the exchanges. While the rules governing different exchange memberships vary, in general the Company’s guarantee obligations would arise only if the exchange had previously exhausted its resources. In addition, any such guarantee obligation would be apportioned among the other non-defaulting members of the exchange. Any potential contingent liability under these membership agreements cannot be estimated. The Company has not recorded any contingent liability in the condensed consolidated financial statements for these agreements and believes that any potential requirement to make payments under these agreements is remote. Self-Insurance On January 1, 2014, the Company entered into a program to self-insure its costs related to medical and dental claims. The Company is self-insured, up to a stop loss amount, for eligible participating employees and retirees, and for qualified dependent medical and dental claims, subject to deductibles and limitations. Liabilities are recognized based on claims filed and an estimate of claims incurred but not reported. The Company has purchased stop-loss coverage to limit its exposure on a per claim basis and in aggregate in the event that aggregated actual claims would exceed 120% of actuarially estimated claims. The Company is insured for covered costs in excess of these limits. Although the ultimate outcome of these matters may exceed the amounts recorded and additional losses may be incurred, the Company does not believe that any additional potential exposure for such liabilities will have a material adverse effect on the Company’s condensed consolidated financial position or results of operations. As of June 30, 2014, the Company had $0.8 million accrued for self-insured medical and dental claims included in ‘accounts payable and other liabilities’ in the condensed consolidated balance sheet.

Commitments and Contingencies

Legal and Regulatory Proceedings

Certain conditions may exist as of the date that the financial statements are issued, which may result in a loss to the Company but which will only be resolved when one or more future events occur or fail to occur. The Company assesses such contingent liabilities, and such assessment inherently involves an exercise of judgment. In assessing loss contingencies related to legal and regulatory proceedings that are pending against the Company or unasserted claims that may result in such proceedings, the Company’s legal counsel evaluates the perceived merits of any legal proceedings or unasserted claims as well as the perceived merits of the amount of relief sought or expected to be sought therein.

If the assessment of a contingency indicates that it is probable that a material loss had been incurred at the date of the financial statements and the amount of the liability can be estimated, then the estimated liability would be accrued in the Company’s financial statements. If the assessment indicates that a potentially material loss contingency is not probable, but is reasonably possible, or is probable but cannot be estimated, then the nature of the contingent liability, together with an estimate of the range of possible loss if determinable and material, would be disclosed. Neither accrual nor disclosure is required for loss contingencies that are deemed remote. The Company accrues legal fees related to contingent liabilities as they are incurred.

In addition to the matters discussed below, from time to time and in the ordinary course of business, the Company is involved in various legal actions and proceedings, including tort claims, contractual disputes, employment matters, workers’ compensation claims and collections. The Company carries insurance that provides protection against certain types of claims, up to the policy limits of the insurance.

As of June 30, 2014 and September 30, 2013, the condensed consolidated balance sheets include loss contingency accruals recorded prior to September 30, 2013 which are not material, individually or in the aggregate, to the Company’s financial position or liquidity. In the opinion of management, possible exposure from loss contingencies in excess of the amounts accrued, and in addition to the possible losses discussed below, is not likely to be material to the Company’s earnings, financial position or liquidity.

The following is a summary of significant legal matters involving the Company.

Securities Litigation and Regulatory Proceedings

On January 13, 2014, a purported class action was filed in the United States District Court for the Southern District of New York against the Company and certain of its officers and directors. The complaint alleges violations of federal securities laws, and claims that the Company has issued false and misleading information concerning the Company’s business and prospects. The action seeks unspecified damages on behalf of persons who purchased the Company’s shares between February 17, 2010 and December 16, 2013. During March 2014, three motions for appointment as lead plaintiff were filed; two were subsequently withdrawn, leaving a single unopposed bid for lead plaintiff appointment, an appointment that was approved by the court on April 29, 2014. The lead plaintiff’s amended complaint was filed on June 13, 2014. The Company’s motion to dismiss the complaint was filed on July 28, 2014. The Company has not determined that losses related to this matter are probable. Because the matter is in the early stages of litigation and no discovery has been commenced, together with the inherent difficulty of predicting the outcome of litigation generally, the Company does not have sufficient information to determine the amount or range of reasonably possible loss with respect to these matters. The Company believes the case is without merit and intends to defend itself vigorously.

The Company’s Directors’ and Officers’ insurance policy is expected to cover any liability and litigation costs in excess of the $0.5 million policy retention amount.

Sentinel Litigation

The Company’s subsidiary, FCStone, LLC, had a portion of its excess segregated funds invested with Sentinel Management Group Inc. (“Sentinel”), a registered FCM and an Illinois-based money manager that provided cash management services to other FCMs. In August 2007, Sentinel halted redemptions to customers and sold certain of the assets it managed to an unaffiliated third party at a significant discount. On August 17, 2007, subsequent to Sentinel’s sale of certain assets, Sentinel filed for bankruptcy protection and $15.5 million of FCStone, LLC’s $21.9 million in invested funds were returned to it.

In August 2008, the bankruptcy trustee of Sentinel filed adversary proceedings against FCStone, LLC, and a number of other FCMs in the Bankruptcy Court for the Northern District of Illinois. The case was subsequently reassigned to the United States District Court, for the Northern District of Illinois. In the complaint, the trustee sought avoidance of alleged transfers or withdrawals of funds received by FCStone, LLC and other FCMs within 90 days prior to the filing of the Sentinel bankruptcy petition, as well as avoidance of post-petition distributions and disallowance of the proof of claim filed by FCStone, LLC. The trustee sought recovery of pre- and post-petition transfers totaling approximately $15.5 million. In April 2009, the trustee filed an amended complaint adding a claim for unjust enrichment. FCStone, LLC answered the complaints and all parties entered into the discovery phase of the litigation. In January 2011, the trustee filed a motion for summary judgment on various counts in the adversary proceedings filed in August 2008 against FCStone, LLC and a number of other FCMs. In January 2012, FCStone, LLC filed a motion for summary judgment in its favor with respect to the transfer of approximately $1.1 million to its customer segregated account on August 17, 2007, pursuant to the “safe harbor” provisions of Section 546(e) of the U.S. Bankruptcy Code. In April 2012, FCStone, LLC filed a motion to dismiss a portion of the trustee’s claims set forth in its amended complaint. The trial of this matter took place, as a test case, during October 2012. The trial court entered a judgment against FCStone, LLC on January 4, 2013. On January 17, 2013, the trial court entered an agreed order, staying execution and enforcement, pending an appeal of the judgment. By agreement, FCStone, LLC was required to post an appeal cash deposit of $8.0 million with the court, which was deposited on January 18, 2013. The oral arguments in the appeal were heard on December 10, 2013. On March 19, 2014 the appeal court ruled in favor of FCStone, LLC. On April 16, 2014, the trustee filed a petition for rehearing of the appeal. On May 19, 2014, the U.S. Court of Appeals for the Seventh Circuit denied the petition. The trustee has until August 18, 2014 to file a writ for certiorari with the U.S. Supreme Court. The Company has not determined that losses related to this matter are probable. The Company believes that if the appellate decision in favor of FCStone, LLC is reversed, the resulting pre-tax loss to FCStone, LLC would be in the range of $4 million to $6 million.

Contractual Commitments

Contingent Liabilities - Acquisitions

Under the terms of the purchase agreements related to the acquisitions listed below, the Company has obligations to pay additional consideration if specific conditions and earnings targets are met. In accordance with the Business Combinations Topic of the ASC, the fair value of the additional consideration is recognized as a contingent liability as of the acquisition date. The contingent liability for these estimated additional purchase price considerations of $8.0 million and $9.6 million are included in ‘accounts payable and other accrued liabilities’ in the condensed consolidated balance sheets as of June 30, 2014 and September 30, 2013. The acquisition date fair value of additional consideration is remeasured to its fair value each reporting period, with changes in fair value recorded in current earnings. The change in fair value during the nine months ended June 30, 2014 and 2013 were increases of $0.1 million and $1.6 million, respectively, and are included in ‘other’ in the consolidated income statements.

The Company has a contingent liability relating to the April 2014 acquisition of Forward Insight Commodities LLC, which may result in the payment of additional purchase price consideration. The contingent liability recorded represents the fair value of the expected consideration to be paid, based on the forecasted adjusted pre-tax net earnings during the twelve-month period following the closing of the acquisition. The present value of the estimated total purchase price, including contingent consideration, is $0.5 million as of June 30, 2014, which remains outstanding and is included in ‘accounts payable and other accrued liabilities’ in the consolidated balance sheet.

The Company has a contingent liability relating to the December 2012 acquisition of the accounts of Tradewire Securities, LLC, which may result in the payment of additional purchase price consideration. The contingent liability recorded represents the fair value of the expected consideration to be paid, based on the forecasted adjusted pre-tax net earnings during three annual periods and a six month period, after the third annual period, following the closing of the acquisition, for a total of four payments, with a discount rate being applied to those future payments. The present value of the estimated total purchase price, including contingent consideration, is $6.3 million as of June 30, 2014, of which $4.8 million remains outstanding and is included in ‘accounts payable and other accrued liabilities’ in the consolidated balance sheet.

The Company has a contingent liability relating to the November 2011 acquisition of Coffee Network, LLC, subsequently reorganized as a division of FCStone, LLC, which may result in the payment of additional purchase price consideration. The contingent liability recorded represents the fair value of the expected consideration to be paid, based on the forecasted adjusted pre-tax net earnings during the three annual periods following the closing of the acquisition plus a final contingent payment. The present value of the estimated total purchase price, including contingent consideration, is less than $0.1 million as of June 30, 2014, which has not been paid and is included in ‘accounts payable and other liabilities’ in the condensed consolidated balance sheet.

The Company has a contingent liability relating to the October 2010 acquisition of Hencorp Becstone Futures, L.C., subsequently reorganized as a division of FCStone, LLC, which may result in the payment of additional purchase price consideration. The contingent liability recorded represents the fair value of the expected consideration to be paid, based on the forecasted adjusted pre-tax net earnings during the fourth fiscal year following the closing of the acquisition plus an additional final estimated contingent payment and a discount rate being applied to the future payments. The present value of the estimated total purchase price, including contingent consideration, is $7.5 million as of June 30, 2014, of which $2.6 million has not been paid and is included in ‘accounts payable and other liabilities’ in the condensed consolidated balance sheet.

Exchange Member Guarantees

The Company is a member of various exchanges that trade and clear futures and option contracts. Associated with its memberships, the Company may be required to pay a proportionate share of the financial obligations of another member who may default on its obligations to the exchanges. While the rules governing different exchange memberships vary, in general the Company’s guarantee obligations would arise only if the exchange had previously exhausted its resources. In addition, any such guarantee obligation would be apportioned among the other non-defaulting members of the exchange. Any potential contingent liability under these membership agreements cannot be estimated. The Company has not recorded any contingent liability in the condensed consolidated financial statements for these agreements and believes that any potential requirement to make payments under these agreements is remote.

Self-Insurance

On January 1, 2014, the Company entered into a program to self-insure its costs related to medical and dental claims. The Company is self-insured, up to a stop loss amount, for eligible participating employees and retirees, and for qualified dependent medical and dental claims, subject to deductibles and limitations. Liabilities are recognized based on claims filed and an estimate of claims incurred but not reported. The Company has purchased stop-loss coverage to limit its exposure on a per claim basis and in aggregate in the event that aggregated actual claims would exceed 120% of actuarially estimated claims. The Company is insured for covered costs in excess of these limits. Although the ultimate outcome of these matters may exceed the amounts recorded and additional losses may be incurred, the Company does not believe that any additional potential exposure for such liabilities will have a material adverse effect on the Company’s condensed consolidated financial position or results of operations. As of June 30, 2014, the Company had $0.8 million accrued for self-insured medical and dental claims included in ‘accounts payable and other liabilities’ in the condensed consolidated balance sheet.