XML 76 R55.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Description of Business and Significant Accounting Policies - Basis of Presentation and Consolidation (Details) - USD ($) | Sep. 30, 2016 | Sep. 30, 2015
--- | --- | ---
Accounting Policies [Abstract] |  |
Cash and Cash Equivalents - Deposits and Receivables | $ 900,000,000 | $ 900,000,000
Preferred Stock, Par or Stated Value Per Share | $ 0.01 | $ 0.01
Preferred Stock, Shares Outstanding | 0 | 0
US Government Securities and Other Securities - Deposits and Receivables | $ 471,738,813 | $ 502,483,279

X
- Definition Cash and Cash Equivalents - Deposits and Receivables + References No definition available. + Details
Name: | intl_CashandCashEquivalentsDepositsandReceivables
Namespace Prefix: | intl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition US Government Securities and Other Securities - Deposits and Receivables + References No definition available. + Details
Name: | intl_USGovernmentSecuritiesandOtherSecuritiesDepositsandReceivables
Namespace Prefix: | intl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 + Details
Name: | us-gaap_PreferredStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 + Details
Name: | us-gaap_PreferredStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant