LOANS (Schedule of Loans Outstanding, by Type of Loan) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Total loans		$ 4,806,721	$ 4,372,437
Loans and Finance Receivables, Gross [Member] | Credit Concentration Risk [Member]
Total loans (in percent)		100.00%	100.00%
Unallocated Financing Receivables [Member]
Total loans		$ 238	$ 225
Unallocated Financing Receivables [Member] | Loans and Finance Receivables, Gross [Member] | Credit Concentration Risk [Member]
Total loans (in percent)		0.01%	0.01%
Residential Mortgage [Member] | Residential Portfolio Segment [Member]
Total loans		$ 498,300	$ 502,829
Residential Mortgage [Member] | Residential Portfolio Segment [Member] | Loans and Finance Receivables, Gross [Member] | Credit Concentration Risk [Member]
Total loans (in percent)		10.37%	11.50%
Multifamily Property [Member] | Residential Portfolio Segment [Member]
Total loans		$ 1,595,866	$ 1,126,946
Multifamily Property [Member] | Residential Portfolio Segment [Member] | Loans and Finance Receivables, Gross [Member] | Credit Concentration Risk [Member]
Total loans (in percent)		33.20%	25.77%
Commercial Mortgage [Member] | Commercial Real Estate Portfolio Segment [Member]
Total loans		$ 662,626	$ 691,294
Commercial Mortgage [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans and Finance Receivables, Gross [Member] | Credit Concentration Risk [Member]
Total loans (in percent)		13.78%	15.81%
Commercial Loans Including Equipment Financing [Member] | Commercial Real Estate Portfolio Segment [Member]
Total loans	[1]	$ 1,955,157	$ 1,950,981
Commercial Loans Including Equipment Financing [Member] | Commercial Real Estate Portfolio Segment [Member] | Loans and Finance Receivables, Gross [Member] | Credit Concentration Risk [Member]
Total loans (in percent)	[1]	40.67%	44.62%
Construction [Member] | Commercial Portfolio Segment [Member]
Total loans		$ 20,044	$ 12,600
Construction [Member] | Commercial Portfolio Segment [Member] | Loans and Finance Receivables, Gross [Member] | Credit Concentration Risk [Member]
Total loans (in percent)		0.42%	0.29%
Home Equity Lines of Credit [Member] | Residential Portfolio Segment [Member]
Total loans		$ 40,803	$ 50,546
Home Equity Lines of Credit [Member] | Residential Portfolio Segment [Member] | Loans and Finance Receivables, Gross [Member] | Credit Concentration Risk [Member]
Total loans (in percent)		0.85%	1.15%
Consumer Loans, Including Home Equity Loans [Member] | Consumer and Other Loans [Member]
Total loans		$ 33,687	$ 37,016
Consumer Loans, Including Home Equity Loans [Member] | Consumer and Other Loans [Member] | Loans and Finance Receivables, Gross [Member] | Credit Concentration Risk [Member]
Total loans (in percent)		0.70%	0.85%

[1] The December 31, 2021 and 2020 balances include PPP loans of $13.8 million and $195.6 million, respectively.