LOANS AND LEASES - Schedule of Loan Modifications, Subsequently Defaulted (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	$ 33.1	$ 2.6
Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	22.0	1.7
Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	1.2	0.3
Balloon Payment
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.6
Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	9.3	0.6
Total commercial loans and leases
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	32.9	2.2
Total commercial loans and leases | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	21.8	1.6
Total commercial loans and leases | Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	1.2	0.0
Total commercial loans and leases | Balloon Payment
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.6
Total commercial loans and leases | Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	9.3	0.6
Total commercial loans and leases | Commercial real estate
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	10.5	0.6
Total commercial loans and leases | Commercial real estate | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.3	0.0
Total commercial loans and leases | Commercial real estate | Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.9	0.0
Total commercial loans and leases | Commercial real estate | Balloon Payment
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.6
Total commercial loans and leases | Commercial real estate | Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	8.7	0.6
Total commercial loans and leases | Commercial and industrial
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	22.4	1.6
Total commercial loans and leases | Commercial and industrial | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	21.5	1.6
Total commercial loans and leases | Commercial and industrial | Term Extension and Rate Reduction
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.3	0.0
Total commercial loans and leases | Commercial and industrial | Balloon Payment
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.0
Total commercial loans and leases | Commercial and industrial | Other
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.6	0.0
Total consumer loans
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.2	0.4
Total consumer loans | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.2	0.1
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 | Balloon Payment
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.0
Total consumer loans | 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	0.2	0.3
Total consumer loans | Residential mortgages | Term Extension
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.2	0.0
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 | Balloon Payment
Financing Receivable, Modified [Line Items]
Total loans that subsequently defaulted	0.0
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