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Revenues From Contracts With Clients Disaggregation of Revenues (Details) - USD ($) | 3 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017
Commissions and clearing fees: |  |
Total commission and clearing fees | $ 97.4 | $ 85.3
Consulting, management, and account fees | 19.1 | 16.6
Total revenues from contracts with clients | 116.5 | 101.9
Sales of physical commodities | 6,295.8 | 7,714.4
Principal gains, net | 94.9 | 78.3
Interest income | 45 | 24
Total revenues | 6,552.2 | 7,918.6
Transferred at Point in Time [Member] |  |
Commissions and clearing fees: |  |
Total revenues from contracts with clients | 94.6 | 82.2
Transferred over Time [Member] |  |
Commissions and clearing fees: |  |
Total revenues from contracts with clients | 21.9 | 19.7
UNITED STATES |  |
Commissions and clearing fees: |  |
Total revenues | 527 | 324
Europe [Member] |  |
Commissions and clearing fees: |  |
Total revenues | 53.3 | 45.2
South America [Member] |  |
Commissions and clearing fees: |  |
Total revenues | 11.4 | 14.9
Middle East and Asia [Domain] |  |
Commissions and clearing fees: |  |
Total revenues | 5,958.7 | 7,533.6
Other (geographic location) [Member] |  |
Commissions and clearing fees: |  |
Total revenues | 1.8 | 0.9
Precious Metals Trading Revenues [Member] |  |
Commissions and clearing fees: |  |
Sales of physical commodities | 5,955.6 | 7,531.9
Physical Commodity Origination and Merchandising [Member] |  |
Commissions and clearing fees: |  |
Sales of physical commodities | 340.2 | 182.5
Sales Based Commissions [Domain] |  |
Commissions and clearing fees: |  |
Total sales-based commissions | 53.4 | 47.9
Sales Based Commissions [Domain] | Exhange-Traded Futures and Options [Member] |  |
Commissions and clearing fees: |  |
Total commission and clearing fees | 39.1 | 34.6
Sales Based Commissions [Domain] | OTC Derivative Brokerage [Member] |  |
Commissions and clearing fees: |  |
OTC derivative brokerage | 8.9 | 7.5
Sales Based Commissions [Domain] | Equities and Fixed Income Commissions [Member] |  |
Commissions and clearing fees: |  |
Total commission and clearing fees | 1.1 | 1.5
Sales Based Commissions [Domain] | Mutual Fund Sales Based Commissions [Member] |  |
Commissions and clearing fees: |  |
Total commission and clearing fees | 2.6 | 2
Sales Based Commissions [Domain] | Variable Annuity [Member] |  |
Commissions and clearing fees: |  |
Total commission and clearing fees | 1.5 | 1.6
Sales Based Commissions [Domain] | Other Sales Based Commissions [Member] |  |
Commissions and clearing fees: |  |
Total commission and clearing fees | 0.2 | 0.7
Trailing Commissions [Domain] |  |
Commissions and clearing fees: |  |
Total commission and clearing fees | 6.9 | 6.9
Trailing Commissions [Domain] | Mutual Fund Trailing Commissions [Member] |  |
Commissions and clearing fees: |  |
Total commission and clearing fees | 3.2 | 3.3
Trailing Commissions [Domain] | Variable Annuity [Member] |  |
Commissions and clearing fees: |  |
Total commission and clearing fees | 3.7 | 3.6
Clearing Fees [Domain] |  |
Commissions and clearing fees: |  |
Clearing fees | 32.6 | 24.9
Trade Conversion Fees [Domain] |  |
Commissions and clearing fees: |  |
Trade conversion fees | 1.6 | 1.8
Other Commissions [Domain] |  |
Commissions and clearing fees: |  |
Trade conversion fees | 2.9 | 3.8
Consulting, management, and account fees [Domain] | Underwriting Fees [Member] |  |
Commissions and clearing fees: |  |
Underwriting fees | 0.3 | 0.7
Consulting, management, and account fees [Domain] | Asset Management Fees [Member] |  |
Commissions and clearing fees: |  |
Consulting, management, and account fees | 6.2 | 6.1
Consulting, management, and account fees [Domain] | Advisory and Consulting Fees [Member] |  |
Commissions and clearing fees: |  |
Consulting, management, and account fees | 5.0 | 4.6
Consulting, management, and account fees [Domain] | Sweep Program Fees [Member] |  |
Commissions and clearing fees: |  |
Consulting, management, and account fees | 3.8 | 2.1
Consulting, management, and account fees [Domain] | Client Account Fees [Member] |  |
Commissions and clearing fees: |  |
Consulting, management, and account fees | 2.7 | 2.8
Consulting, management, and account fees [Domain] | Other Consulting, Management, and Account Fees [Member] |  |
Commissions and clearing fees: |  |
Consulting, management, and account fees | $ 1.1 | $ 0.3

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- Definition Revenue from clearing fees. Clearing fees are charged by an exchange for each contract and trade cleared. There are also clearing fees associated with deliveries, creation of a futures position resulting from an option exercise or assignment, Exchange for Physicals (EFP), block trades, transfer trades and adjustments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1(e)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
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