XML 67 R56.htm IDEA: XBRL DOCUMENT
v3.19.2

Employee Incentive Plans (Share Grants And Fair Value) (Details) - USD ($) $ in Millions | 12 Months Ended | 104 Months Ended | 140 Months Ended
--- | --- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2018
Employee Incentive Plans [Abstract] |  |  |  |  |  |
Shares granted | 1,146,267 | [1] | 946,489 | 1,451,136 | 22,100,001 |
Fair Value - Date of Grant | $ 62 |  | $ 57 | $ 55 | $ 449 | $ 62
Shares Granted IPO to Date |  |  |  |  |  | 25,643,893
Fair Value - Date of Grant IPO to Date |  |  |  |  |  | $ 623
[1] | Stock Incentive Plan number of granted restricted stock units related to 2018 was adjusted by 640 additional restricted stock units during the six months ended June 30, 2019.

X
- Definition Fair Value of shares granted under the 2007 Stock Incentive Plan. + References No definition available. + Details
Name: | ibkr_FairValueShareBasedCompensationSIPSharesGranted
Namespace Prefix: | ibkr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair Value of all shares granted under the 2007 Stock Incentive Plan from the IPO to date. + References No definition available. + Details
Name: | ibkr_FairValueShareBasedCompensationSIPSharesGrantedIPOToDate
Namespace Prefix: | ibkr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of shares granted under the 2007 Stock Incentive Plan. + References No definition available. + Details
Name: | ibkr_ShareBasedCompensationSharesGranted
Namespace Prefix: | ibkr_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Shares granted under the Stock Incentive Plan from the IPO to date. + References No definition available. + Details
Name: | ibkr_ShareBasedCompensationSharesGrantedIPOToDate
Namespace Prefix: | ibkr_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration