Loan Portfolio and Allowance for Credit Losses, Recorded Investment in Loans by Loan Class (Details) - USD ($) $ in Thousands		Mar. 31, 2023	Dec. 31, 2022		Mar. 31, 2022
Loans and Leases Receivable [Abstract]
Total loans		$ 4,799,582	$ 4,733,201
Allowance for credit losses on loans		46,685	46,032		$ 46,178
Net loans		4,752,897	4,687,169
New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans	[1]	3,214,052	3,219,914	[2]
Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		1,585,530	1,513,287
Real Estate Construction Loans [Member]
Loans and Leases Receivable [Abstract]
Total loans		30,700	36,400
Residential Borrowers [Member]
Loans and Leases Receivable [Abstract]
Total loans		8,300	14,100
Commercial Borrowers Residential Purpose [Member]
Loans and Leases Receivable [Abstract]
Total loans		22,400	22,300
Commercial [Member]
Loans and Leases Receivable [Abstract]
Total loans		246,307	231,011
Allowance for credit losses on loans		2,708	2,596		2,177
Commercial [Member] | Commercial Real Estate [Member]
Loans and Leases Receivable [Abstract]
Total loans		223,131	209,922
Commercial [Member] | Commercial Real Estate [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans	[1]	182,287	177,371	[2]
Commercial [Member] | Commercial Real Estate [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		40,844	32,551
Commercial [Member] | Other [Member]
Loans and Leases Receivable [Abstract]
Total loans		23,176	21,089
Commercial [Member] | Other [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans	[1]	22,365	20,221	[2]
Commercial [Member] | Other [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		811	868
Commercial [Member] | PPP Loans [Member]
Loans and Leases Receivable [Abstract]
Total loans		854			3,000
Real Estate Mortgage - 1 to 4 Family [Member]
Loans and Leases Receivable [Abstract]
Total loans		4,537,949	4,489,883
Allowance for credit losses on loans		43,766	43,271		43,931
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member]
Loans and Leases Receivable [Abstract]
Total loans		4,184,751	4,146,902
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans	[1]	2,760,159	2,776,989	[2]
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		1,424,592	1,369,913
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member]
Loans and Leases Receivable [Abstract]
Total loans		56,708	56,549
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans	[1]	44,112	43,999	[2]
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		12,596	12,550
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member]
Loans and Leases Receivable [Abstract]
Total loans		296,490	286,432
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans	[1]	193,645	191,926	[2]
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		102,845	94,506
Installment [Member]
Loans and Leases Receivable [Abstract]
Total loans		15,326	12,307
Allowance for credit losses on loans		211	165		$ 70
Installment [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans	[1]	11,484	9,408	[2]
Installment [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		$ 3,842	$ 2,899

[1] Includes New York, New Jersey, Vermont and Massachussetts.

[2] Includes New York, New Jersey, Vermont and Massachusetts.