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Receivables From Customers, Net and Notes Receivable, Net (Notes) | 3 Months Ended
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Dec. 31, 2019
Receivables from customers and notes receivable, net [Abstract] |
Financing Receivables [Text Block] | Allowance for Doubtful Accounts The allowance for doubtful accounts related to deposits with and receivables from broker-dealers, clearing organizations, and counterparties was $36.9 million as of December 31, 2019 and September 30, 2019. The allowance for doubtful accounts related to receivables from clients was $11.6 million and $11.7 million as of December 31, 2019 and September 30, 2019, respectively. The Company had no allowance for doubtful accounts related to notes receivable as of December 31, 2019 and September 30, 2019. During the three months ended December 31, 2019, the Company recorded bad debt expense of less than $0.1 million. During the three months ended December 31, 2018, the Company recorded bad debt expense of $0.3 million. Additionally, during the three months ended December 31, 2018, the Company reached settlements with clients, paying $8.4 million related to demurrage, dead freight, and other penalty charges regarding coal supplied during fiscal 2017. The settlement amount paid was less than the accrued liability for the transactions recorded during fiscal 2017 and fiscal 2018, and accordingly the Company recorded a recovery on the bad debt on physical coal of $2.4 million in the three months ended December 31, 2018.

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- Definition Receivables from customers and notes receivable, net [Abstract] + References No definition available. + Details
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- Definition The entire disclosure for allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -URI http://asc.fasb.org/topic&trid=2196771 + Details
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