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Regulatory Requirements and Subsidiary Dividend Restrictions - Minimum Regulatory Net Capital (Details) | Sep. 30, 2021 USD ($)
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Capital and Other Regulatory Requirements [Abstract] |
Adjusted net capital | $ 10,000,000
Capital and Other Regulatory Requirements [Line Items] |
Actual | 20,000,000
Minimum Requirement | 10,000,000
StoneX Financial Inc. |
Capital and Other Regulatory Requirements [Abstract] |
Adjusted net capital | 1,500,000
Capital and Other Regulatory Requirements [Line Items] |
Actual | 311,200,000
Minimum Requirement | 198,900,000
StoneX Financial Ltd. |
Capital and Other Regulatory Requirements [Line Items] |
Actual | 368,500,000
Minimum Requirement | 218,400,000
Gain Capital Group, LLC |
Capital and Other Regulatory Requirements [Abstract] |
Adjusted net capital | 1,000,000
Capital and Other Regulatory Requirements [Line Items] |
Actual | 49,400,000
Minimum Requirement | 30,100,000
StoneX Financial Pte. Ltd. |
Capital and Other Regulatory Requirements [Line Items] |
Actual | 45,400,000
Minimum Requirement | $ 15,900,000

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- Definition Capital and Other Regulatory Requirements [Abstract] + References No definition available. + Details
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- Definition Capital and Other Regulatory Requirements [Line Items] + References No definition available. + Details
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- Definition Minimum amount of net capital required to be maintained by broker-dealer subsidiary to engage in security transaction, calculated under Aggregate Indebtedness Standard. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher SEC -Name Rule 15c3-1 -Number 240 -Section 15c3-1 + Details
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- Definition Amount of adjusted net capital of futures commission merchant (FCM) per Commodity Futures Trading Commission's (CFTC) requirement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher CFTC -Name Rule 17 -Number 1 -Section 17 -Paragraph (c) -Subparagraph (5) + Details
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- Definition Amount of net capital required to be maintained by futures commission merchant (FCM) per Commodity Futures Trading Commission's (CFTC) requirement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher CFTC -Name Rule 17 -Number 1 -Section 17 -Paragraph (a) -Subparagraph (1)(i) + Details
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