v2.4.0.8

Financial Assets And Financial Liabilities (Level 3 Financial Liabilities) (Details) (USD $) In Thousands, unless otherwise specified | 6 Months Ended
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Jun. 30, 2014
Financial Liabilities Level 3 Rollforward [Abstract] |
Beginning balance | $ 3
Transfers in and/or out of Level 3 (Liabilities) | 74
Ending balance | $ 77

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- Details
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Namespace Prefix: | ibkr_
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- Definition Amount of transfers of financial instrument classified as a liability into (out of) level 3 of the fair value hierarchy. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
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- Definition Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258 + Details
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Period Type: | instant