Loan Portfolio and Allowance for Credit Losses - Amortized Cost Basis of Loans Modified to Borrowers Experiencing Financial Difficulty (Details) - Payment Delay [Member] - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 283	$ 302	$ 797	$ 685
% of Total Class of Financing Receivable		0.01%	0.01%	0.02%	0.01%
Installment [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 0	$ 0	$ 0	$ 0
% of Total Class of Financing Receivable		0.00%	0.00%	0.00%	0.00%
New York And Other States [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified	[1]	$ 0	$ 213	$ 514	$ 512
% of Total Class of Financing Receivable	[1]	0.00%	0.01%	0.02%	0.02%
New York And Other States [Member] | Installment [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified	[1]	$ 0	$ 0	$ 0	$ 0
% of Total Class of Financing Receivable	[1]	0.00%	0.00%	0.00%	0.00%
Florida [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 283	$ 89	$ 283	$ 173
% of Total Class of Financing Receivable		0.00%	0.00%	0.00%	0.01%
Florida [Member] | Installment [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 0	$ 0	$ 0	$ 0
% of Total Class of Financing Receivable		0.00%	0.00%	0.00%	0.00%
Commercial Real Estate [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 0	$ 0	$ 0	$ 0
% of Total Class of Financing Receivable		0.00%	0.00%	0.00%	0.00%
Commercial Real Estate [Member] | New York And Other States [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified	[1]	$ 0	$ 0	$ 0	$ 0
% of Total Class of Financing Receivable	[1]	0.00%	0.00%	0.00%	0.00%
Commercial Real Estate [Member] | Florida [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 0	$ 0	$ 0	$ 0
% of Total Class of Financing Receivable		0.00%	0.00%	0.00%	0.00%
Other [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 0	$ 0	$ 0	$ 0
% of Total Class of Financing Receivable		0.00%	0.00%	0.00%	0.00%
Other [Member] | New York And Other States [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified	[1]	$ 0	$ 0	$ 0	$ 0
% of Total Class of Financing Receivable	[1]	0.00%	0.00%	0.00%	0.00%
Other [Member] | Florida [Member] | Commercial [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 0	$ 0	$ 0	$ 0
% of Total Class of Financing Receivable		0.00%	0.00%	0.00%	0.00%
First Mortgages [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 283	$ 80	$ 675	$ 354
% of Total Class of Financing Receivable		0.01%	0.00%	0.03%	0.01%
First Mortgages [Member] | New York And Other States [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified	[1]	$ 0	$ 80	$ 392	$ 270
% of Total Class of Financing Receivable	[1]	0.00%	0.00%	0.01%	0.01%
First Mortgages [Member] | Florida [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 283	$ 0	$ 283	$ 84
% of Total Class of Financing Receivable		0.02%	0.00%	0.02%	0.01%
Home Equity Loans [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 0	$ 89	$ 0	$ 89
% of Total Class of Financing Receivable		0.00%	0.16%		0.16%
Home Equity Loans [Member] | New York And Other States [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified	[1]	$ 0	$ 0	$ 0	$ 0
% of Total Class of Financing Receivable	[1]	0.00%	0.00%	0.00%	0.00%
Home Equity Loans [Member] | Florida [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 0	$ 89	$ 0	$ 89
% of Total Class of Financing Receivable		0.00%	0.67%	0.00%	0.67%
Home Equity Line of Credit [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 0	$ 133	$ 122	$ 242
% of Total Class of Financing Receivable		0.00%	0.03%	0.00%	0.06%
Home Equity Line of Credit [Member] | New York And Other States [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified	[1]	$ 0	$ 133	$ 122	$ 242
% of Total Class of Financing Receivable	[1]	0.00%	0.06%	0.05%	0.10%
Home Equity Line of Credit [Member] | Florida [Member] | Real Estate Mortgage - 1 to 4 Family [Member]
Loan Portfolio and Allowance for Credit Losses [Abstract]
Loans modified		$ 0	$ 0	$ 0	$ 0
% of Total Class of Financing Receivable		0.00%	0.00%	0.00%	0.00%

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