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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(c)(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Loans - Consumer, Excluding Credit Card Loan Portfolio (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025	Sep. 30, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total retained loans	$ 1,497,159	$ 1,408,905	$ 1,369,785
Consumer, excluding credit card
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total retained loans	367,206	368,741	$ 369,859
Consumer, excluding credit card \| Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total retained loans	299,642	303,531
Consumer, excluding credit card \| Auto and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total retained loans	$ 67,564	$ 65,210