Loans and Allowance for Loan Losses, Impaired Receivables (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2016	Dec. 31, 2015
Impaired loans by loans class [Abstract]
Recorded Investment	$ 25,687	$ 25,881
Unpaid Principal Balance	28,144	28,209
Related Allowance	0	0
Average Recorded Investment	27,679	26,552
Commercial [Member] \| Commercial Real Estate [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	3,040	3,306
Unpaid Principal Balance	3,993	3,996
Related Allowance	0	0
Average Recorded Investment	4,828	3,608
Commercial [Member] \| Other [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
Real Estate Mortgage - 1 to 4 Family [Member] \| First Mortgages [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	19,522	19,220
Unpaid Principal Balance	20,678	20,454
Related Allowance	0	0
Average Recorded Investment	19,425	19,616
Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Loans [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	351	412
Unpaid Principal Balance	410	470
Related Allowance	0	0
Average Recorded Investment	372	436
Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Lines of Credit [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	2,774	2,943
Unpaid Principal Balance	3,063	3,289
Related Allowance	0	0
Average Recorded Investment	3,054	2,892
New York and Other States [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	23,033	23,431
Unpaid Principal Balance	25,294	25,584
Related Allowance	0	0
Average Recorded Investment	25,137	24,355
New York and Other States [Member] \| Commercial [Member] \| Commercial Real Estate [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	3,040	3,306
Unpaid Principal Balance	3,993	3,996
Related Allowance	0	0
Average Recorded Investment	4,828	3,608
New York and Other States [Member] \| Commercial [Member] \| Other [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
New York and Other States [Member] \| Real Estate Mortgage - 1 to 4 Family [Member] \| First Mortgages [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	17,529	17,460
Unpaid Principal Balance	18,573	18,602
Related Allowance	0	0
Average Recorded Investment	17,553	18,127
New York and Other States [Member] \| Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Loans [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	299	359
Unpaid Principal Balance	358	417
Related Allowance	0	0
Average Recorded Investment	320	382
New York and Other States [Member] \| Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Lines of Credit [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	2,165	2,306
Unpaid Principal Balance	2,370	2,569
Related Allowance	0	0
Average Recorded Investment	2,436	2,238
Florida [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	2,654	2,450
Unpaid Principal Balance	2,850	2,625
Related Allowance	0	0
Average Recorded Investment	2,542	2,197
Florida [Member] \| Commercial [Member] \| Commercial Real Estate [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
Florida [Member] \| Commercial [Member] \| Other [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
Florida [Member] \| Real Estate Mortgage - 1 to 4 Family [Member] \| First Mortgages [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	1,993	1,760
Unpaid Principal Balance	2,105	1,852
Related Allowance	0	0
Average Recorded Investment	1,872	1,489
Florida [Member] \| Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Loans [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	52	53
Unpaid Principal Balance	52	53
Related Allowance	0	0
Average Recorded Investment	52	54
Florida [Member] \| Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Lines of Credit [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	609	637
Unpaid Principal Balance	693	720
Related Allowance	0	0
Average Recorded Investment	$ 618	$ 654

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5258-111524

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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953550-111524

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