XML 62 R51.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Employee Incentive Plans (2007 Stock Incentive Plan, ROI Summary) (Details) | 6 Months Ended
--- | ---
Jun. 30, 2016 shares
2007 Stock Incentive Plan (Shares) |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Beginning Balance | 8,937,519 | [1]
Shares Forfeited | (55,653) |
Shares Distributed | (2,395,177) |
Ending Balance | 6,486,689 |
2007 ROI Unit Stock Plan (Shares) [Member] |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Beginning Balance | 6,370 |
Shares Distributed | (997) |
Ending Balance | 5,373 |
[1] | Stock Incentive Plan number of granted shares related to 2015 was adjusted by 11,988 additional shares during the six months ended June 30, 2016.

X
- Definition Shares granted, net of shares distributed and forfeited. + References No definition available. + Details
Name: | ibkr_NetShares
Namespace Prefix: | ibkr_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total shares distributed during the period. + References No definition available. + Details
Name: | ibkr_SharesDistributed
Namespace Prefix: | ibkr_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Shares forfeited during the period. + References No definition available. + Details
Name: | ibkr_SharesForfeited
Namespace Prefix: | ibkr_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- 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
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=ibkr_StockIncentivePlanSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=ibkr_TwoThousandSevenRoiUnitStockPlanSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |