Regulatory Requirements and Subsidiary Dividend Restrictions - Minimum net capital (Details)	Sep. 30, 2019 USD ($)
Minimum Net Capital Required for Broker-Dealer Subsidiary	$ 1,000,000
Minimum Net Capital Required for Entity	0.08
INTL FCStone Financial [Member]
Net Capital under Commodity Exchange Act Computation	170,100,000
Required Net Capital under Commodity Exchange Act	97,500,000
INTL FCStone, Ltd [Member]
Net Capital under Commodity Exchange Act Computation	231,700,000
Required Net Capital under Commodity Exchange Act	$ 123,300,000

Minimum amount of net capital required to be maintained by entity's broker-dealer subsidiary to engage in securities transactions.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

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- Definition

Minimum amount of net capital required to be maintained by the entity to engage in securities transactions.

+ References

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-Publisher SEC
-Name Rule 15c3-1
-Number 240
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- Definition

The amount of net capital calculated under the Commodity Futures Trading Commission's minimum financial requirements, pursuant to the Commodity Exchange Act, less the market value of certain commodity options.

+ References

No definition available.

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- Definition

Amount of net capital required to be maintained under the Commodity Futures Trading Commission's (CFTC) minimum financial requirements, pursuant to the Commodity Exchange Act, less the market value of certain commodity options.

+ References

No definition available.

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