Regulatory Requirements (Summary Of Capital, Capital Requirements And Excess Capital) (Details) $ in Millions	Jun. 30, 2025 USD ($)
Net Capital / Eligible Equity	$ 15,513
Requirement	2,215
Excess	13,298
IB LLC [Member]
Net Capital / Eligible Equity	9,739
Requirement	1,308
Excess	8,431
IBHK [Member]
Net Capital / Eligible Equity	1,501
Requirement	397
Excess	1,104
IBIE [Member]
Net Capital / Eligible Equity	1,703
Requirement	336
Excess	1,367
Other Regulated Operating Companies [Member]
Net Capital / Eligible Equity	2,570
Requirement	174
Excess	$ 2,396

Eligible equity is equal to the sum of audited capital and reserves and the eligible portion of subordinated debt. Net capital is equal to the net worth of the broker dealer, less certain items such as exchange memberships, carrying value of securities not readily marketable, haircuts on marketable securities in proprietary accounts, furniture and equipment and other illiquid assets as defined.

No definition available.

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- Definition

Minimum amount of net capital required to be maintained by broker-dealer parent, calculated under Aggregate Indebtedness Standard.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Rule 15c3-1
-Number 240
-Section 15c3-1
-Publisher SEC

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- Definition

Amount of total risk-based capital exceeding minimum required for capital adequacy as defined by regulatory framework.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1

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