Financial Instruments Subject to Off-Balance Sheet Credit Risk - Summary of the Fair Value of Client Securities Available to Utilize as Collateral and Amounts Pledged (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Securities Financing Transaction [Line Items]
Fair value of client securities available to be pledged	$ 228,200	$ 155,500
Total collateral pledged to third parties	148,229	79,286
Fulfillment of requirements with the Options Clearing Corporation
Securities Financing Transaction [Line Items]
Total collateral pledged to third parties	52,440	34,791
Fulfillment of client short sales
Securities Financing Transaction [Line Items]
Total collateral pledged to third parties	51,886	16,196
Securities lending to other broker-dealers
Securities Financing Transaction [Line Items]
Total collateral pledged to third parties	37,482	23,867
Collateral for secured short-term borrowings
Securities Financing Transaction [Line Items]
Total collateral pledged to third parties	2,484	4,376
Collateral for repurchase agreements
Securities Financing Transaction [Line Items]
Total collateral pledged to third parties	3,937	56
Fully Paid Client Securities
Securities Financing Transaction [Line Items]
Total collateral pledged to third parties	$ 265	$ 217

Fair value of collateral permitted, by contact or custom, to be sold or re-pledged.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481420/860-30-50-1A

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- Definition

Fair value of the collateral, or portion thereof, that has been re-pledged, delivered, or otherwise used.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481420/860-30-50-1A

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 20
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-20

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