LOANS AND LEASES - Loan Modifications, Subsequently Defaulted (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	$ 1.0	$ 4.0	$ 4.2	$ 4.0
Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.7		2.7
Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.1		0.6
Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.2		0.9
Total commercial loans and leases
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.8	3.0	3.6	3.0
Total commercial loans and leases | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.5		2.4
Total commercial loans and leases | Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.1		0.3
Total commercial loans and leases | Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.2		0.9
Total commercial loans and leases | Commercial real estate
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.2	3.0	1.3	3.0
Total commercial loans and leases | Commercial real estate | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.0		0.4
Total commercial loans and leases | Commercial real estate | Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.0		0.0
Total commercial loans and leases | Commercial real estate | Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.2		0.9
Total commercial loans and leases | Commercial and industrial
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.6	0.0	2.3	0.0
Total commercial loans and leases | Commercial and industrial | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.5		2.0
Total commercial loans and leases | Commercial and industrial | Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.1		0.3
Total commercial loans and leases | Commercial and industrial | Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.0		0.0
Total consumer loans
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.2	1.0	0.6	1.0
Total consumer loans | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.2		0.3
Total consumer loans | Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.0		0.3
Total consumer loans | Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.0		0.0
Total consumer loans | Direct installment
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.1	0.0	0.1	0.0
Total consumer loans | Direct installment | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.1		0.1
Total consumer loans | Direct installment | Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.0		0.0
Total consumer loans | Direct installment | Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.0		0.0
Total consumer loans | Residential mortgages
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.1	$ 1.0	0.4	$ 1.0
Total consumer loans | Residential mortgages | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.1		0.1
Total consumer loans | Residential mortgages | Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.0		0.3
Total consumer loans | Residential mortgages | Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	$ 0.0		0.0
Total consumer loans | Consumer lines of credit
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted			0.1
Total consumer loans | Consumer lines of credit | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted			0.1
Total consumer loans | Consumer lines of credit | Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted			0.0
Total consumer loans | Consumer lines of credit | Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted			$ 0.0