Loans and Allowance for Loan Losses, Risk Category of Loans (Details) - USD ($) $ in Thousands		Mar. 31, 2021		Dec. 31, 2020
Loans and Leases Receivable [Abstract]
Total loans, net		$ 4,269,172		$ 4,244,470
Impaired loans included in classified loans		471		796
New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net	[1]	3,062,023		3,061,352
Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		1,207,149		1,183,118
Commercial [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		217,021		212,492
Commercial [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		198,667	[2]	193,707
Commercial [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		18,354		18,785
Commercial [Member] | Pass [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		213,661		208,474
Commercial [Member] | Pass [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		195,877	[2]	190,263
Commercial [Member] | Pass [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		17,784		18,211
Commercial [Member] | Classified [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		3,360		4,018
Commercial [Member] | Classified [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		2,790	[2]	3,444
Commercial [Member] | Classified [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		570		574
Commercial [Member] | Commercial Real Estate [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		164,983		167,441
Commercial [Member] | Commercial Real Estate [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net	[1]	146,994	[2]	148,775
Commercial [Member] | Commercial Real Estate [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		17,989		18,666
Commercial [Member] | Commercial Real Estate [Member] | Pass [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		161,852		163,833
Commercial [Member] | Commercial Real Estate [Member] | Pass [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		144,433	[2]	145,741
Commercial [Member] | Commercial Real Estate [Member] | Pass [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		17,419		18,092
Commercial [Member] | Commercial Real Estate [Member] | Classified [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		3,131		3,608
Commercial [Member] | Commercial Real Estate [Member] | Classified [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		2,561	[2]	3,034
Commercial [Member] | Commercial Real Estate [Member] | Classified [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		570		574
Commercial [Member] | Other [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		52,038		45,051
Commercial [Member] | Other [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net	[1]	51,673	[2]	44,932
Commercial [Member] | Other [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		365		119
Commercial [Member] | Other [Member] | Pass [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		51,809		44,641
Commercial [Member] | Other [Member] | Pass [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		51,444	[2]	44,522
Commercial [Member] | Other [Member] | Pass [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		365		119
Commercial [Member] | Other [Member] | Classified [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		229		410
Commercial [Member] | Other [Member] | Classified [Member] | New York and Other States [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		229	[2]	410
Commercial [Member] | Other [Member] | Classified [Member] | Florida [Member]
Loans and Leases Receivable [Abstract]
Total loans, net		$ 0		$ 0

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

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