Debt Instrument, Discount Rate at Issuance of Face Value

No definition available.

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Namespace Prefix:	intl_
Data Type:	dtr-types:percentItemType
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Period Type:	instant

- Definition

Debt Instrument Remaining Outstanding

+ References

No definition available.

+ Details

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Namespace Prefix:	intl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

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+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

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+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Percentage of principal amount of debt redeemed.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash outflow for a long-term debt where the holder has highest claim on the entity's asset in case of bankruptcy or liquidation during the period.

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Balance Type:	credit
Period Type:	duration

- Details

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- Details

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- Details

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Credit Facilities - Senior Secured Notes due 2025 (Details) - USD ($)		1 Months Ended	12 Months Ended
	Sep. 01, 2020	Jun. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Debt Instrument [Line Items]
Debt instrument offering price, percentage		98.50%
Debt instrument, redemption price, percentage	100.00%	108.625%	100.00%
Debt instrument, redemption price, percentage of principal amount redeemed		40.00%
Repayments of senior secured notes			$ 1,600,000	$ 92,100,000	$ 0
Debt instrument remaining outstanding			500,000
Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount	$ 91,500,000		$ 100,000,000
Debt instrument, redemption price, percentage		100.00%	103.00%
Debt instrument, redemption price, percentage of principal amount redeemed			103.00%
Debt instrument, conversion price (in dollars per share)			$ 6.00
Senior Notes \| Gain Capital Holdings Inc
Debt Instrument [Line Items]
Debt instrument, face amount			$ 92,000,000
Debt instrument, interest rate, stated percentage		5.00%	5.00%
Debt instrument remaining outstanding		$ 500,000
Senior Notes Due Twenty Twenty Five
Debt Instrument [Line Items]
Debt instrument, face amount		$ 350,000,000
Debt instrument, interest rate, stated percentage		8.625%	8.625%
Debt issuance costs, gross			$ 9,500,000
Debt instrument, redemption price, percentage			103.00%
Repayments of senior secured notes			$ 1,600,000