SIGNIFICANT ACCOUNTING POLICIES - Loan Servicing (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2025	Dec. 31, 2024
Accounting Policies [Abstract]
Unpaid principal balances of loans serviced			$ 667.9	$ 582.5
Mortgage servicing rights sold		$ 923.5
Pre-tax gain on debt securities		7.5
Debt securities, available for sale, sold	$ 205.6	108.2
Pre-tax loss on sale of debt securities available for sale	$ 15.5	$ 6.8
Impairment charges			$ 0.2	$ 0.0