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v3.3.1.900

Goodwill (Notes) | 3 Months Ended
--- | ---
Dec. 31, 2015
Goodwill [Abstract] |
Goodwill Disclosure [Text Block] | Goodwill The carrying value of goodwill is allocated to the Company’s operating segments as follows:
(in millions) | December 31, 2015 |  | September 30, 2015
Commercial Hedging | $ | 30.7 |  |  | $ | 30.7 |
Global Payments | 6.3 |  |  | 6.3 |
Physical Commodities | 2.4 |  |  | 2.4 |
Securities | 8.1 |  |  | 8.1 |
Goodwill | $ | 47.5 |  |  | $ | 47.5 |

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- Definition Goodwill [Abstract] + References No definition available. + Details
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Namespace Prefix: | intl_
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Period Type: | duration

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- Definition The entire disclosure for goodwill. + References No definition available. + Details
Name: | us-gaap_GoodwillDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration