LOANS, LEASES, AND ALLOWANCE FOR CREDIT LOSSES (Collateral-Dependent Loans) (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost	$ 69	$ 66
Commercial and industrial \| Commercial: \| Equipment and machinery
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost	$ 1
Weighted average LTV	101.00%
Owner-occupied \| Commercial: \| Industrial building
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost	$ 9
Weighted average LTV	56.00%
Owner-occupied \| Commercial: \| Retail facility
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost		$ 6
Weighted average LTV		64.00%
Municipal \| Commercial: \| Multifamily apartments
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost	$ 5	$ 5
Weighted average LTV	169.00%	174.00%
Term \| Commercial real estate: \| Office building
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost	$ 51	$ 49
Weighted average LTV	96.00%	98.00%
1-4 family residential \| Consumer: \| Single family residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost	$ 3	$ 3
Weighted average LTV	48.00%	38.00%
Home equity credit line \| Consumer: \| Single family residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost		$ 3
Weighted average LTV		29.00%