LOANS AND LEASES - Gross Charge-offs of Loans and Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	$ 31	$ 38
Year two	84	79
Year three	124	142
Year four	95	71
Year five	34	26
Prior	71	79
Revolver Gross Charge-offs	36	52
Revolver Converted to Term Loans Gross Charge-offs	51	44
Total	526	531	$ 454
Commercial portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
Total	288	311	270
Consumer portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
Total	238	220	$ 184
Commercial and industrial | Commercial portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	7	4
Year two	26	26
Year three	69	74
Year four	62	38
Year five	12	14
Prior	20	19
Revolver Gross Charge-offs	33	47
Revolver Converted to Term Loans Gross Charge-offs	7	3
Total	236	225
Commercial real estate | Commercial portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	2	12
Year two	8	4
Year three	13	31
Year four	1	3
Year five	0	0
Prior	16	25
Revolver Gross Charge-offs	1	4
Revolver Converted to Term Loans Gross Charge-offs	0	0
Total	41	79
Lease financing | Commercial portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0	2
Year two	1	2
Year three	2	0
Year four	4	2
Year five	2	0
Prior	2	1
Revolver Gross Charge-offs	0	0
Revolver Converted to Term Loans Gross Charge-offs	0	0
Total	11	7
Residential mortgage | Consumer portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
Prior	4	3
Revolver Gross Charge-offs	0	0
Revolver Converted to Term Loans Gross Charge-offs	0	0
Total	4	3
Automobile | Consumer portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	8	5
Year two	22	18
Year three	17	17
Year four	16	14
Year five	10	5
Prior	4	4
Revolver Gross Charge-offs	0	0
Revolver Converted to Term Loans Gross Charge-offs	0	0
Total	77	63
Home equity | Consumer portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0	0
Year two	0	0
Year three	0	0
Year four	0	0
Year five	0	0
Prior	0	1
Revolver Gross Charge-offs	2	1
Revolver Converted to Term Loans Gross Charge-offs	4	4
Total	6	6
RV and marine | Consumer portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0	1
Year two	3	4
Year three	7	5
Year four	5	7
Year five	6	4
Prior	12	10
Revolver Gross Charge-offs	0	0
Revolver Converted to Term Loans Gross Charge-offs	0	0
Total	33	31
Other consumer | Consumer portfolio
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	14	14
Year two	24	25
Year three	16	15
Year four	7	7
Year five	4	3
Prior	13	16
Revolver Gross Charge-offs	0	0
Revolver Converted to Term Loans Gross Charge-offs	40	37
Total	$ 118	$ 117