XML 72 R57.htm IDEA: XBRL DOCUMENT
v3.19.3

Employee Incentive Plans (2007 Stock Incentive Plan, ROI Summary) (Details) - 2007 Stock Incentive Plan (Shares) | 9 Months Ended
--- | ---
Sep. 30, 2019 shares | [1]
Beginning Balance | 5,472,706
Shares Cancelled | (71,829)
Shares Distributed | (1,626,825)
Ending Balance | 3,774,052
[1] | Stock Incentive Plan number of granted restricted stock units related to 2018 was adjusted by 640 additional restricted stock units during the nine months ended September 30, 2019.

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