LOANS AND SERVICING - Loans modified and classified as troubled debt restructures (Details)	3 Months Ended	12 Months Ended
Mar. 31, 2017 USD ($) item	Dec. 31, 2016 USD ($) item
Loans modified and classified as troubled debt restructures
Non-accrual Loans	$ 937,000	$ 953,000
Loans receivable	$ 281,669,000	$ 279,492,000
Number of loan modifications that resulted in the classification of TDR \| item	0
Number of TDRs in default of their modified terms \| item	0	0
Commitments to lend additional funds to borrowers with modified loans	$ 0
Residential loans:
Loans modified and classified as troubled debt restructures
Loan modifications	$ 157,000
Number of loans \| item	1
Loans receivable	$ 108,337,000	$ 106,069,000
One- to four- family, residential loans
Loans modified and classified as troubled debt restructures
Non-accrual Loans	742,000	755,000
Loans receivable	92,869,000	90,190,000
Home equity loans and lines of credit
Loans modified and classified as troubled debt restructures
Non-accrual Loans	195,000	198,000
Loans receivable	15,468,000	15,879,000
Commercial loans:
Loans modified and classified as troubled debt restructures
Loans receivable	151,855,000	148,087,000
One-to-four family investment property
Loans modified and classified as troubled debt restructures
Loans receivable	14,400,000	13,081,000
Multi-family real estate
Loans modified and classified as troubled debt restructures
Loans receivable	30,214,000	30,748,000
Commercial real estate
Loans modified and classified as troubled debt restructures
Loans receivable	83,390,000	83,583,000
Commercial business loan
Loans modified and classified as troubled debt restructures
Loans receivable	23,851,000	20,675,000
Construction loans
Loans modified and classified as troubled debt restructures
Loans receivable	21,327,000	25,154,000
One-to-four family, construction loans
Loans modified and classified as troubled debt restructures
Loans receivable	9,368,000	12,599,000
Multi-family
Loans modified and classified as troubled debt restructures
Loans receivable	4,505,000	5,725,000
Non-residential
Loans modified and classified as troubled debt restructures
Loans receivable	7,454,000	6,830,000
Consumer
Loans modified and classified as troubled debt restructures
Loans receivable	$ 150,000	$ 182,000

Commitments to lend additional funds to borrowers with modified loans.

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Represents the number of contracts in financing receivables.

+ References

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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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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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- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953682-111524

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- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ 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
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-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5111-111524

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Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(3))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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