LOANS - Corporate Loan Modifications to Borrowers Experiencing Financial Difficulty (Details) - Corporate loans - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 279	$ 133	$ 403	$ 151
Commitments to lend	624	355	624	355
Term extension
Financing Receivable, Modified [Line Items]
Total modifications balance	256	133	380	151
Combination: term extension and payment delay
Financing Receivable, Modified [Line Items]
Total modifications balance	23	0	23	0
Commercial and industrial
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 228	$ 133	$ 324	$ 151
Weighted average term extension	11 months	12 months	11 months	13 months
Commercial and industrial \| Term extension
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 205	$ 133	$ 301	$ 151
Commercial and industrial \| Combination: term extension and payment delay
Financing Receivable, Modified [Line Items]
Total modifications balance	23	0	23	0
Financial institutions
Financing Receivable, Modified [Line Items]
Total modifications balance	0	0	0	0
Financial institutions \| Term extension
Financing Receivable, Modified [Line Items]
Total modifications balance	0	0	0	0
Financial institutions \| Combination: term extension and payment delay
Financing Receivable, Modified [Line Items]
Total modifications balance	0	0	0	0
Mortgage and real estate
Financing Receivable, Modified [Line Items]
Total modifications balance	51	0	63	0
Mortgage and real estate \| Term extension
Financing Receivable, Modified [Line Items]
Total modifications balance	51	0	63	0
Mortgage and real estate \| Combination: term extension and payment delay
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 0	0	$ 0	0
Weighted average term extension	35 months		34 months
Other
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 0	0	$ 16	0
Other \| Term extension
Financing Receivable, Modified [Line Items]
Total modifications balance	0	0	16	0
Other \| Combination: term extension and payment delay
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 0	$ 0	$ 0	$ 0
Weighted average term extension			46 months

Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty.

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