XML 57 R45.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Goodwill (Tables) | 3 Months Ended
--- | ---
Dec. 31, 2018
Goodwill [Abstract] |
Schedule of Goodwill [Table Text Block] | The carrying value of goodwill is allocated to the Company’s operating segments as follows:
(in millions) | December 31, 2018 |  | September 30, 2018
Commercial Hedging | $ | 30.3 |  |  | $ | 30.3 |
Global Payments | 8.9 |  |  | 8.9 |
Physical Commodities | 2.4 |  |  | 2.4 |
Securities | 7.0 |  |  | 6.8 |
Goodwill | $ | 48.6 |  |  | $ | 48.4 |

X
- Definition Goodwill [Abstract] + References No definition available. + Details
Name: | intl_GoodwillAbstract
Namespace Prefix: | intl_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13854-109267 + Details
Name: | us-gaap_ScheduleOfGoodwillTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration