LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($) loan	Jun. 30, 2021 USD ($) loan	Jun. 30, 2022 USD ($) loan	Jun. 30, 2021 USD ($) loan	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit loss	$ 40,543,000	$ 36,908,000	$ 40,543,000	$ 36,908,000	$ 38,117,000	$ 37,588,000	$ 35,555,000	$ 34,340,000
Loans receivable	3,909,753,000		3,909,753,000			3,634,792,000
Provision for credit loss expense	2,905,000	1,967,000	4,548,000	4,089,000
Allowance for unfunded commitments	0	$ 0	586,000	$ 0
Amortized cost in troubled debt restructurings	17,800,000		17,800,000			16,600,000
Financing receivable, troubled debt restructuring, allowance for loans	$ 2,600,000		$ 2,600,000			2,600,000
Financing receivable, modifications, number of contracts | loan	0	1	1	3
Minimum period to be considered for loan to have defaulted			90 days
Loans modified as troubled debt restructuring with subsequent defaults | loan	0	0	0	0
Principal balances forgiven in connection with loan restructuring	$ 0	$ 0	$ 0	$ 0
PPP loans, net of deferred processing fees
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans receivable	2,287,000		2,287,000			45,203,000
Syndicated loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans receivable	153,154,000		153,154,000			125,761,000
Commercial and Industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit loss	9,555,000	$ 7,312,000	9,555,000	$ 7,312,000	$ 9,090,000	8,837,000	$ 6,479,000	$ 6,233,000
Loans receivable	759,417,000		759,417,000			708,989,000
Financing receivable, modifications, number of contracts | loan		1		1
Commercial and Industrial | PPP loans, net of deferred processing fees
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit loss	0		0			0
Loans receivable	2,300,000		2,300,000			45,200,000
Commercial and Industrial | Syndicated loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans receivable	$ 153,200,000		$ 153,200,000			$ 125,800,000