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Namespace Prefix:	ibkr_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	ibkr_FinancialInstrumentsOwnedAndPledgedAsCollateralAmountEligibleToBeRepledgedByCounterpartyAbstract
Namespace Prefix:	ibkr_
Data Type:	xbrli:stringItemType
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Period Type:	duration

Fair value of stocks held by the entity for its own account (proprietary securities) for trading or investment purposes that are carried at fair value and pledged to counterparties as collateral for financing transactions where counterparty has the right to re-pledge such.

No definition available.

Name:	ibkr_StockOwnedAndPledgedAsCollateralAmountEligibleToBeRepledgedByCounterparty
Namespace Prefix:	ibkr_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

Fair value of U.S. and foreign government obligations held by the entity for its own account (proprietary securities) for trading or investment purposes that are carried at fair value and pledged to counterparties as collateral for financing transactions where counterparty has the right to re-pledge such.

No definition available.

Name:	ibkr_USForeignGovernmentObligationsOwnedAndPledgedAsCollateralAmountEligibleToBeRepledgedByCounterparty
Namespace Prefix:	ibkr_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

Fair value of warrants held by the entity for its own account (proprietary securities) for trading or investment purposes that are carried at fair value and pledged to counterparties as collateral for financing transactions where counterparty has the right to re-pledge such.

No definition available.

Name:	ibkr_WarrantsOwnedAndPledgedAsCollateralAmountEligibleToBeRepledgedByCounterparty
Namespace Prefix:	ibkr_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

Fair value of financial instrument held by the entity for its own account (proprietary securities) for trading or investment purposes that are carried at fair value and pledged to counterparties as collateral for financing transactions where counterparty has the right to re-pledge such.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6467456&loc=d3e113888-111728

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 140

-Paragraph 15

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.