Loans and Allowance for Loan Losses, Impaired Receivables (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2017	Dec. 31, 2016
Impaired loans by loans class [Abstract]
Recorded Investment	$ 25,386	$ 24,025
Unpaid Principal Balance	27,674	26,201
Related Allowance	0	0
Average Recorded Investment	24,231	22,408
Commercial [Member] \| Commercial Real Estate [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	2,322	2,418
Unpaid Principal Balance	3,514	3,470
Related Allowance	0	0
Average Recorded Investment	2,282	2,214
Commercial [Member] \| Other [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	100	0
Unpaid Principal Balance	100	0
Related Allowance	0	0
Average Recorded Investment	100	0
Real Estate Mortgage - 1 to 4 Family [Member] \| First Mortgages [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	19,868	18,684
Unpaid Principal Balance	20,694	19,539
Related Allowance	0	0
Average Recorded Investment	18,868	17,465
Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Loans [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	368	363
Unpaid Principal Balance	404	399
Related Allowance	0	0
Average Recorded Investment	363	332
Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Lines of Credit [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	2,728	2,560
Unpaid Principal Balance	2,962	2,793
Related Allowance	0	0
Average Recorded Investment	2,618	2,397
New York and Other States [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	22,627	21,361
Unpaid Principal Balance	24,752	23,374
Related Allowance	0	0
Average Recorded Investment	20,844	19,936
New York and Other States [Member] \| Commercial [Member] \| Commercial Real Estate [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	2,322	2,418
Unpaid Principal Balance	3,514	3,470
Related Allowance	0	0
Average Recorded Investment	2,282	2,214
New York and Other States [Member] \| Commercial [Member] \| Other [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	100	0
Unpaid Principal Balance	100	0
Related Allowance	0	0
Average Recorded Investment	100	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	17,791	16,675
Unpaid Principal Balance	18,526	17,439
Related Allowance	0	0
Average Recorded Investment	16,154	15,665
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	275	269
Unpaid Principal Balance	311	305
Related Allowance	0	0
Average Recorded Investment	269	251
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	2,139	1,999
Unpaid Principal Balance	2,301	2,160
Related Allowance	0	0
Average Recorded Investment	2,039	1,806
Florida [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	2,759	2,664
Unpaid Principal Balance	2,922	2,827
Related Allowance	0	0
Average Recorded Investment	3,387	2,472
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	2,077	2,009
Unpaid Principal Balance	2,168	2,100
Related Allowance	0	0
Average Recorded Investment	2,714	1,800
Florida [Member] \| Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Loans [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	93	94
Unpaid Principal Balance	93	94
Related Allowance	0	0
Average Recorded Investment	94	81
Florida [Member] \| Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Lines of Credit [Member]
Impaired loans by loans class [Abstract]
Recorded Investment	589	561
Unpaid Principal Balance	661	633
Related Allowance	0	0
Average Recorded Investment	$ 579	$ 591

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=66008989&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=66008989&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=66008989&loc=SL6953550-111524

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5212-111524

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