Loans and Allowance for Loan Losses, Troubled Debt Restructurings (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019 USD ($) Contract	Jun. 30, 2018 USD ($) Contract	Jun. 30, 2019 USD ($) Contract	Jun. 30, 2018 USD ($) Contract	Dec. 31, 2018 USD ($)
Financing Receivable Modifications Information [Abstract]
TDR's classifications from previously performing loans		$ 11,200		$ 11,200		$ 11,100
New York and Other States [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract	[1]	9	2	13	6
Pre-Modification Outstanding Recorded Investment	[1]	$ 1,124	$ 125	$ 1,774	$ 806
Post-Modification Outstanding Recorded Investment	[1]	$ 1,124	$ 125	$ 1,774	$ 806
Florida [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract		0	0	0	0
Pre-Modification Outstanding Recorded Investment		$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment		$ 0	$ 0	$ 0	$ 0
Commercial [Member] | Commercial Real Estate [Member] | New York and Other States [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract	[1]	1	0	1	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 128	$ 0	$ 128	$ 0
Post-Modification Outstanding Recorded Investment	[1]	$ 128	$ 0	$ 128	$ 0
Commercial [Member] | Commercial Real Estate [Member] | Florida [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract		0	0	0	0
Pre-Modification Outstanding Recorded Investment		$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment		$ 0	$ 0	$ 0	$ 0
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member] | New York and Other States [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract	[1]	5	2	9	4
Pre-Modification Outstanding Recorded Investment	[1]	$ 718	$ 125	$ 1,368	$ 598
Post-Modification Outstanding Recorded Investment	[1]	$ 718	$ 125	$ 1,368	$ 598
Real Estate Mortgage - 1 to 4 Family [Member] | First Mortgages [Member] | Florida [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract		0	0	0	0
Pre-Modification Outstanding Recorded Investment		$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment		$ 0	$ 0	$ 0	$ 0
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member] | New York and Other States [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract	[1]	0	0	0	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0	$ 0
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Loans [Member] | Florida [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract		0	0	0	0
Pre-Modification Outstanding Recorded Investment		$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment		$ 0	$ 0	$ 0	$ 0
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member] | New York and Other States [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract	[1]	3	0	3	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 278	$ 0	$ 278	$ 208
Post-Modification Outstanding Recorded Investment	[1]	$ 278	$ 0	$ 278	$ 208
Real Estate Mortgage - 1 to 4 Family [Member] | Home Equity Lines of Credit [Member] | Florida [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract		0	0	0	0
Pre-Modification Outstanding Recorded Investment		$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment		$ 0	$ 0	$ 0	$ 0

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