XML 68 R57.htm IDEA: XBRL DOCUMENT v3.19.2

Employee Incentive Plans (2007 Stock Incentive Plan, ROI Summary) (Details) - 2007 Stock Incentive Plan (Shares)	6 Months Ended
	Jun. 30, 2019 shares	[1]
Beginning Balance	5,472,706
Shares Cancelled	(8,904)
Shares Distributed	(1,626,384)
Ending Balance	3,837,418
[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

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: