LOANS AND ALLOWANCE FOR CREDIT LOSSES ON LOANS (Narrative) (Details) $ in Thousands	3 Months Ended		6 Months Ended	12 Months Ended
	Mar. 31, 2023 USD ($) loan	Mar. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
SBA PPP Loans, Originations, Number of Contracts Outstanding | loan	5			5
Loans and Leases Receivable, Related Parties, Description	At March 31, 2023 and December 31, 2022, outstanding loans to certain officers, directors and their associated companies were less than 5% of the Company's shareholders' equity.			At March 31, 2023 and December 31, 2022, outstanding loans to certain officers, directors and their associated companies were less than 5% of the Company's shareholders' equity.
Proceeds from the sale of mortgage loans	$ 35,501	$ 47,771
Gain on sale of mortgage loans	(384)	(1,132)
Loans held for sale, at fair value (book value of $4,539 and $5,259, respectively)	4,562			$ 5,197
Allowance for Loan and Lease Losses, Period Increase (Decrease)	200
Allowance for credit losses	37,134	31,785		36,922	$ 33,256
(Credit) provision for loan losses	$ 439	(1,221)	$ 4,430
Other industry exposures	0
Non-Accrual Loans	$ 2,958			2,991
Loans outstanding	4,073,108			4,010,353
Interest lost on nonaccrual loans	25	46
Loans and Leases Receivable, Excluded Accrued Interest from Amortized Cost	11,000			10,300
Recorded Investment				$ 2,566
Loans modified | loan				0
FHLB advances, general debt obligations, pledged collateral	1,800,000			$ 1,800,000
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,733,147			1,700,266
Allowance for credit losses	10,812	6,476		9,089	6,133
(Credit) provision for loan losses	1,737	343	3,022
Non-Accrual Loans	1,715			1,733
Loans outstanding	1,733,147			1,700,266
Mortgage Loans in Process of Foreclosure, Amount	450			481
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	421,099			430,131
Allowance for credit losses	4,581	4,857		5,446	4,202
(Credit) provision for loan losses	(652)	843	1,907
Non-Accrual Loans	748			715
Loans outstanding	421,099			430,131
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	232,512			234,428
Allowance for credit losses	2,440	1,435		2,225	1,469
(Credit) provision for loan losses	215	(34)	669
Non-Accrual Loans	438			486
Loans outstanding	232,512			234,428
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	19,733			20,591
Allowance for credit losses	507	106		504	$ 79
(Credit) provision for loan losses	4	92	$ 552
Non-Accrual Loans	0			0
Loans outstanding	19,733			20,591
Fixed Rate Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from the sale of mortgage loans	35,100	46,600
Gain on sale of mortgage loans	(384)	(1,100)
Loans held for sale, at fair value (book value of $4,539 and $5,259, respectively)	4,500			5,300
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	421,099			430,131
Recorded Investment				0
Financing Receivable, Year One, Originated, Current Fiscal Year	14,185			73,686
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	68,796			70,162
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	66,132			32,498
SBA PPP Portfolio
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	583			648
Nonoperating Income (Expense) | Fixed Rate Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gain on sale of mortgage loans	85	142
Unrealized gain (loss) on loans held for sale	$ 23	$ (62)
Non-Residential Building Operators Industry Sector | Loan Concentration Risk | Total Loan Portfolio
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (percentage)	13.00%
Non-Residential Building Operators Industry Sector | Loan Concentration Risk | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (percentage)	32.00%
Residential Building Operators Industry Sector | Loan Concentration Risk | Total Loan Portfolio
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (percentage)	12.00%
Residential Building Operators Industry Sector | Loan Concentration Risk | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (percentage)	28.00%
Substandard [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 4,347			5,156
Financing Receivable, Year One, Originated, Current Fiscal Year	192			149
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	229			52
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	88			133
Pass [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	416,161			423,274
Financing Receivable, Year One, Originated, Current Fiscal Year	13,993			73,537
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	68,567			70,110
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	$ 66,044			32,272
Performing Financial Instruments [Member] | Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment				2,100
Nonperforming Financial Instruments [Member] | Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment				$ 452