LEASES - Summary of Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Components of lease expense:
Operating lease cost (resulting from lease payments)	$ 2,712	$ 2,738	$ 5,427	$ 5,504
Supplemental cash flow information related to leases:
Operating cash flows from operating leases	2,861	2,893	5,749	5,832
ROU assets obtained in the exchange for lease liabilities due to new leases and acquisitions	0	0	703	0
Supplemental balance sheet information related to leases:
Operating lease ROU assets	50,397		50,397		$ 48,910
Operating lease liabilities	$ 58,568		$ 58,568		$ 57,402
Operating lease, right-of-use asset, statement of financial position	Other assets		Other assets		Other assets
Operating lease, liability, statement of financial position	Accrued interest payable and other liabilities		Accrued interest payable and other liabilities		Accrued interest payable and other liabilities
Other information related to leases:
Weighted average remaining lease term of operating leases	8 years 3 months 18 days		8 years 3 months 18 days		8 years 7 months 6 days
Weighted average discount rate of operating leases	3.22%		3.22%		3.02%
Revere Bank And RPJ
Supplemental cash flow information related to leases:
ROU assets obtained in the exchange for lease liabilities due to new leases and acquisitions	$ 0	$ 0	$ 0	$ 0