XML 73 R58.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Employee Incentive Plans (2007 Stock Incentive Plan, ROI Summary) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
2007 Stock Incentive Plan (Shares) |  |  |  |  |  |
Beginning Balance |  | 7,917,719 |  | 8,937,985 |  | 10,376,800
Shares Granted |  | 923,407 | [1] | 1,451,136 | [2] | 1,211,533
Shares Cancelled |  | (115,711) |  | (69,340) |  | (163,221)
Shares Distributed |  | (2,274,777) |  | (2,402,062) |  | (2,487,127)
Ending Balance |  | 6,450,638 |  | 7,917,719 |  | 8,937,985
Intrinsic Value Of SIP Shares Which Vested And Were Distributed [Member] |  |  |  |  |  |
Distributed | [3] | $ 81 |  | $ 88 |  | $ 86
2007 ROI Unit Stock Plan (Shares) [Member] |  |  |  |  |  |
Beginning Balance |  | 4,994 |  | 6,370 |  | 9,614
Shares Distributed |  | (1,145) |  | (1,376) |  | (3,244)
Ending Balance |  | 3,849 |  | 4,994 |  | 6,370
[1] | Granted under the Company's amended 2007 Stock Incentive Plan, pending stockholder approval at the Company's 2018 Annual Meeting.
[2] | Stock Incentive Plan number of granted restricted stock units related to 2016 was adjusted by 5,657 additional restricted stock units during the year ended December 31, 2017.
[3] | Intrinsic value of SIP units distributed represents the compensation value reported to the participants.

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 Intrinsic value of SIP shares distributed represents the compensation value reported to the participants. + References No definition available. + Details
Name: | ibkr_SharesDistributedIntrinsicValue
Namespace Prefix: | ibkr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Shares cancelled 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 Shares granted during the period. + References No definition available. + Details
Name: | ibkr_StockPlanCompensationSharesGranted
Namespace Prefix: | ibkr_
Data Type: | xbrli:sharesItemType
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_IntrinsicValueOfSipSharesWhichVestedAndWereDistributedMember
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: |