BORROWINGS (Trust Preferred Securities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Junior Subordinated Debentures [Member]
Debt Instrument [Line Items]
Face Amount	$ 61.0	$ 61.0
Junior Subordinated Debentures [Member] | Capital Trust V Preferred Securities Due in 2037 [Member]
Debt Instrument [Line Items]
Face Amount	$ 50.0
Basis spread on variable rate	1.48%
Fixed rate	5.46%
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust I Securities Due in 2034 [Member]
Debt Instrument [Line Items]
Face Amount	$ 5.1
Basis spread on variable rate	2.44%
Fixed rate	6.42%
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust II Securities Due in 2037 [Member]
Debt Instrument [Line Items]
Face Amount	$ 5.9
Basis spread on variable rate	1.65%
Fixed rate	5.63%
Subordinated Debt [Member]
Debt Instrument [Line Items]
Face Amount	$ 300.0
Fixed rate	7.25%