LOANS - Corporate Loan Modifications to Borrowers Experiencing Financial Difficulty (Details) - Corporate $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 76
Commitments to lend	368
Term extension
Financing Receivable, Modified [Line Items]
Total modifications balance	46
Combination: term extension and payment delay
Financing Receivable, Modified [Line Items]
Total modifications balance	30
Commercial and industrial
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 70
Weighted average term extension	15 months
Commercial and industrial | Term extension
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 40
Commercial and industrial | Combination: term extension and payment delay
Financing Receivable, Modified [Line Items]
Total modifications balance	30
Financial institutions
Financing Receivable, Modified [Line Items]
Total modifications balance	0
Financial institutions | Term extension
Financing Receivable, Modified [Line Items]
Total modifications balance	0
Financial institutions | Combination: term extension and payment delay
Financing Receivable, Modified [Line Items]
Total modifications balance	0
Mortgage and real estate
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 6
Weighted average term extension	4 months
Mortgage and real estate | Term extension
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 6
Mortgage and real estate | Combination: term extension and payment delay
Financing Receivable, Modified [Line Items]
Total modifications balance	0
Other
Financing Receivable, Modified [Line Items]
Total modifications balance	0
Other | Term extension
Financing Receivable, Modified [Line Items]
Total modifications balance	0
Other | Combination: term extension and payment delay
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 0