LOANS - Non-Accrual Corporate Loans (Details) - Corporate loans - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Financing Receivable, Impaired [Line Items]
Recorded investment	$ 722		$ 722		$ 953
Related specific allowance	308		308		323
Non-accrual loans for which there is no ACLL	1,025		1,025		1,048
Interest income recognized	5	$ 6	17	$ 14
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Recorded investment	529		529		788
Related specific allowance	225		225		295
Non-accrual loans for which there is no ACLL	482		482		353
Financial institutions
Financing Receivable, Impaired [Line Items]
Recorded investment	10		10		0
Related specific allowance	3		3		0
Non-accrual loans for which there is no ACLL	50		50		65
Mortgage and real estate
Financing Receivable, Impaired [Line Items]
Recorded investment	19		19		44
Related specific allowance	9		9		4
Non-accrual loans for which there is no ACLL	407		407		583
Other
Financing Receivable, Impaired [Line Items]
Recorded investment	164		164		121
Related specific allowance	71		71		24
Non-accrual loans for which there is no ACLL	$ 86		$ 86		$ 47

Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest, Nonaccrual

No definition available.

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- Definition

Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477657/942-210-S45-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478478/942-210-S50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7)(e)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

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- Definition

Amortized cost excluding accrued interest, of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

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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

No definition available.

+ Details

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- Definition

Amount of interest income on financing receivable on nonaccrual status.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

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