Loans and Allowance for Loan Losses (Details) - USD ($) $ in Thousands		Jun. 30, 2021		Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable [Abstract]
Total loans, net		$ 4,349,367			$ 4,244,470
Less: Allowance for loan losses		50,155		$ 49,991	49,595	$ 48,144	$ 46,155	$ 44,317
Net loans		4,299,212			4,194,875
New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net	[1]	3,097,436			3,061,352
Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		1,251,931			1,183,118
Real Estate Construction Loans [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		33,100			24,700
Residential Borrowers [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		16,900			10,500
Commercial Borrowers Residential Purpose [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		16,200			14,200
Commercial [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		214,164			212,492
Less: Allowance for loan losses		4,106		4,052	4,140	4,366	3,960	3,999
Commercial [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		195,163	[2]		193,707
Commercial [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		19,001			18,785
Commercial [Member] | Commercial Real Estate [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		164,823			167,441
Commercial [Member] | Commercial Real Estate [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net	[1]	146,430	[2]		148,775
Commercial [Member] | Commercial Real Estate [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		18,393			18,666
Commercial [Member] | Other [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		49,341			45,051
Commercial [Member] | Other [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net	[1]	48,733	[2]		44,932
Commercial [Member] | Other [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		608			119
Commercial [Member] | PPP Loans [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		32,500			28,900
Real Estate Mortgage - 1 to 4 Family [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		4,126,565			4,022,361
Less: Allowance for loan losses		45,617		45,507	44,950	43,274	41,643	39,748
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		3,828,087			3,705,696
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net	[1]	2,662,813			2,606,781
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		1,165,274			1,098,915
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		64,264			74,471
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, net	[1]	50,593			59,400
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		13,671			15,071
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		234,214			242,194
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, net	[1]	181,921			193,654
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		52,293			48,540
Installment [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		8,638			9,617
Less: Allowance for loan losses		432		$ 432	505	$ 504	$ 552	$ 570
Installment [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net	[1]	6,946			7,810
Installment [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		$ 1,692			$ 1,807

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

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