BORROWINGS - Subordinated Notes (Details) - Subordinated Debt - USD ($) $ in Millions	Apr. 01, 2024	Jun. 02, 2022	Jun. 01, 2020	Jun. 30, 2024
5.25% Notes Maturing June 1, 2030
Debt Instrument [Line Items]
Issuance of debt			$ 125.0
Interest rate			5.25%
Duration of fixed interest rate			5 years
Floating interest rate margin (as a percent)			5.11%
5.000% Notes Maturing June 15, 2032
Debt Instrument [Line Items]
Issuance of debt		$ 100.0
Floating interest rate margin (as a percent)		2.52%
Fixed to floating interest rate (as a percent)		5.00%
Percentage of principal amount of notes		100.00%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR)
5.25% Notes Maturing December 4, 2030 | Merchants and Manufacturers Bank Corporation
Debt Instrument [Line Items]
Issuance of debt	$ 4.0
Floating interest rate margin (as a percent)	4.97%
Fixed to floating interest rate (as a percent)	5.25%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR)
Fair value discount outstanding				$ 0.1