Loans and Allowance for Loan Losses, Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($) Contract	Sep. 30, 2016 USD ($) Contract	Sep. 30, 2017 USD ($) Contract	Sep. 30, 2016 USD ($) Contract	Dec. 31, 2016 USD ($)
Financing Receivable, Modifications [Line Items]
TDR's classifications from previously performing loans	$ 11,000		$ 11,000		$ 11,500
New York and Other States [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract	10	10	37	38
Pre-Modification Outstanding Recorded Investment	$ 1,237	$ 882	$ 5,203	$ 2,743
Post-Modification Outstanding Recorded Investment	$ 1,237	$ 882	$ 5,203	$ 2,743
Florida [Member]
Modified loans by class determined to be TDR's [Abstract]
Number of Contracts | Contract	2	0	8	4
Pre-Modification Outstanding Recorded Investment	$ 251	$ 0	$ 788	$ 459
Post-Modification Outstanding Recorded Investment	$ 251	$ 0	$ 788	$ 459
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	0	0	3	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 747	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 747	$ 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	7	7	25	27
Pre-Modification Outstanding Recorded Investment	$ 941	$ 655	$ 3,986	$ 2,383
Post-Modification Outstanding Recorded Investment	$ 941	$ 655	$ 3,986	$ 2,383
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	2	0	7	2
Pre-Modification Outstanding Recorded Investment	$ 251	$ 0	$ 718	$ 408
Post-Modification Outstanding Recorded Investment	$ 251	$ 0	$ 718	$ 408
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	0	1	1	1
Pre-Modification Outstanding Recorded Investment	$ 0	$ 44	$ 13	$ 44
Post-Modification Outstanding Recorded Investment	$ 0	$ 44	$ 13	$ 44
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	1
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 45
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 45
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	3	2	8	10
Pre-Modification Outstanding Recorded Investment	$ 296	$ 183	$ 457	$ 316
Post-Modification Outstanding Recorded Investment	$ 296	$ 183	$ 457	$ 316
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	1	1
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 70	$ 6
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 70	$ 6