Loans and Allowance for Loan Losses, Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	$ 44,162	$ 44,064	$ 43,890	$ 44,762
Loans charged off [Abstract]
Total loan charge offs	847	967	2,103	3,569
Recoveries of loans previously charged off [Abstract]
Total recoveries	217	103	595	407
Net loans charged off	630	864	1,508	3,162
Provision (credit) for loan losses	550	750	1,700	2,350
Balance at end of period	44,082	43,950	44,082	43,950
New York and Other States [Member]
Loans charged off [Abstract]
Total loan charge offs	812	962	1,917	3,446
Recoveries of loans previously charged off [Abstract]
Total recoveries	145	101	523	403
Florida [Member]
Loans charged off [Abstract]
Total loan charge offs	35	5	186	123
Recoveries of loans previously charged off [Abstract]
Total recoveries	72	2	72	4
Commercial [Member]
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	4,596	5,046	4,929	4,491
Loans charged off [Abstract]
Total loan charge offs	0	356	72	688
Recoveries of loans previously charged off [Abstract]
Total recoveries	0	3	8	44
Net loans charged off	0	353	64	644
Provision (credit) for loan losses	24	505	(245)	1,351
Balance at end of period	4,620	5,198	4,620	5,198
Commercial [Member] | New York and Other States [Member]
Loans charged off [Abstract]
Total loan charge offs	0	356	72	688
Recoveries of loans previously charged off [Abstract]
Total recoveries	0	3	8	44
Commercial [Member] | Florida [Member]
Loans charged off [Abstract]
Total loan charge offs	0	0	0	0
Recoveries of loans previously charged off [Abstract]
Total recoveries	0	0	0	0
Real Estate Mortgage - 1 to 4 Family [Member]
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	38,871	38,589	38,231	39,753
Loans charged off [Abstract]
Total loan charge offs	778	551	1,866	2,631
Recoveries of loans previously charged off [Abstract]
Total recoveries	209	80	566	317
Net loans charged off	569	471	1,300	2,314
Provision (credit) for loan losses	434	(51)	1,805	628
Balance at end of period	38,736	38,067	38,736	38,067
Real Estate Mortgage - 1 to 4 Family [Member] | New York and Other States [Member]
Loans charged off [Abstract]
Total loan charge offs	747	549	1,699	2,528
Recoveries of loans previously charged off [Abstract]
Total recoveries	137	78	494	313
Real Estate Mortgage - 1 to 4 Family [Member] | Florida [Member]
Loans charged off [Abstract]
Total loan charge offs	31	2	167	103
Recoveries of loans previously charged off [Abstract]
Total recoveries	72	2	72	4
Installment [Member]
Allowance for loan losses by portfolio segment [Roll Forward]
Balance at beginning of period	695	429	730	518
Loans charged off [Abstract]
Total loan charge offs	69	60	165	250
Recoveries of loans previously charged off [Abstract]
Total recoveries	8	20	21	46
Net loans charged off	61	40	144	204
Provision (credit) for loan losses	92	296	140	371
Balance at end of period	726	685	726	685
Installment [Member] | New York and Other States [Member]
Loans charged off [Abstract]
Total loan charge offs	65	57	146	230
Recoveries of loans previously charged off [Abstract]
Total recoveries	8	20	21	46
Installment [Member] | Florida [Member]
Loans charged off [Abstract]
Total loan charge offs	4	3	19	20
Recoveries of loans previously charged off [Abstract]
Total recoveries	$ 0	$ 0	$ 0	$ 0