Loan Portfolio and Allowance for Credit Losses, Recorded Investment in Loans by Loan Class (Details) - USD ($) $ in Thousands		Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022
Loans and Leases Receivable [Abstract]
Total loans		$ 4,886,811		$ 4,733,201
Allowance for credit losses on loans		46,914	$ 46,685	46,032	$ 45,285	$ 46,178
Net loans		4,839,897		4,687,169
New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans	[1]	3,221,910		3,219,914
Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		1,664,901		1,513,287
Real Estate Construction Loans [Member]
Loans and Leases Receivable [Abstract]
Total loans		27,000		36,400
Residential Borrowers [Member]
Loans and Leases Receivable [Abstract]
Total loans		6,300		14,100
Commercial Borrowers Residential Purpose [Member]
Loans and Leases Receivable [Abstract]
Total loans		20,700		22,300
Commercial [Member]
Loans and Leases Receivable [Abstract]
Total loans		251,434		231,011
Allowance for credit losses on loans		2,610	2,708	2,596	2,274	2,177
Commercial [Member] | Commercial Real Estate [Member]
Loans and Leases Receivable [Abstract]
Total loans		229,548		209,922
Commercial [Member] | Commercial Real Estate [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans	[1]	190,361		177,371
Commercial [Member] | Commercial Real Estate [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		39,187		32,551
Commercial [Member] | Other [Member]
Loans and Leases Receivable [Abstract]
Total loans		21,886		21,089
Commercial [Member] | Other [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans	[1]	21,566		20,221
Commercial [Member] | Other [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		320		868
Commercial [Member] | PPP Loans [Member]
Loans and Leases Receivable [Abstract]
Total loans		760		1,000
Real Estate Mortgage - 1 to 4 Family [Member]
Loans and Leases Receivable [Abstract]
Total loans		4,618,981		4,489,883
Allowance for credit losses on loans		44,067	43,766	43,271	42,880	43,931
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member]
Loans and Leases Receivable [Abstract]
Total loans		4,252,144		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]	2,755,040		2,776,989
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		1,497,104		1,369,913
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member]
Loans and Leases Receivable [Abstract]
Total loans		57,861		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]	44,841		43,999
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		13,020		12,550
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member]
Loans and Leases Receivable [Abstract]
Total loans		308,976		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]	198,067		191,926
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		110,909		94,506
Installment [Member]
Loans and Leases Receivable [Abstract]
Total loans		16,396		12,307
Allowance for credit losses on loans		237	$ 211	165	$ 131	$ 70
Installment [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans	[1]	12,035		9,408
Installment [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans		$ 4,361		$ 2,899

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