LOANS RECEIVABLE AND CREDIT QUALITY, Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2017 USD ($) Loan	Mar. 31, 2016 Loan	Dec. 31, 2016 USD ($) Loan
Troubled Debt Restructuring on Receivables [Abstract]
Number of loans modified	0	0
Number of loan committed to borrowers	0		0
TDRs which defaulted within twelve months following the modification	0	0
Real Estate Loans [Member]
Troubled Debt Restructuring on Receivables [Abstract]
Number of loans	7		7
Balance \| $	$ 8,638		$ 8,689
Real Estate Loans [Member] \| One- to Four-Family Residential, Including Condominium and Cooperative Apartment [Member]
Troubled Debt Restructuring on Receivables [Abstract]
Number of loans	2		2
Balance \| $	$ 402		$ 407
Real Estate Loans [Member] \| Multifamily Residential and Residential Mixed Use [Member]
Troubled Debt Restructuring on Receivables [Abstract]
Number of loans	3		3
Balance \| $	$ 649		$ 658
Real Estate Loans [Member] \| Commercial Mixed Use Real Estate [Member]
Troubled Debt Restructuring on Receivables [Abstract]
Number of loans	1		1
Balance \| $	$ 4,240		$ 4,261
Real Estate Loans [Member] \| Commercial Real Estate [Member]
Troubled Debt Restructuring on Receivables [Abstract]
Number of loans	1		1
Balance \| $	$ 3,347		$ 3,363

Number of financing receivables that have been commitments to borrowers with outstanding troubled debt restructurings.

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- Definition

Number of loans modified in a manner that met the criteria of a TDR.

+ References

No definition available.

+ Details

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- Definition

The number of TDR loans that have defaulted within twelve months following modification.

+ References

No definition available.

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- References

No definition available.

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524

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- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

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