FAIR VALUE MEASUREMENTS - Unobservable Inputs Non-recurring (Details) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2017	Dec. 31, 2016
Quantitative information about the significant unobservable inputs within Level 3
Other real estate owned	$ 363,000	$ 90,000
Non-recurring \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Total	11,010,000	6,804,000
Non-recurring \| Fair value of collateral - appraised value \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Impaired loans	3,037,000	3,268,000
Other real estate owned	363,000	90,000
Non-recurring \| Discount cash flow \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Impaired loans	4,217,000	3,441,000
Capitalized servicing rights	3,393,000	5,000
Non-recurring \| Impaired loans \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Impaired loans	$ 7,254,000	$ 6,709,000
Non-recurring \| Impaired loans \| Minimum \| Fair value of collateral - appraised value \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Loss severity	0.00%	0.00%
Appraised value	$ 0	$ 0
Non-recurring \| Impaired loans \| Minimum \| Discount cash flow \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Discount rate	2.88%	3.25%
Cash flows	$ 5,000	$ 6,000
Non-recurring \| Impaired loans \| Maximum \| Fair value of collateral - appraised value \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Loss severity	75.00%	51.00%
Appraised value	$ 1,732,000	$ 1,732,000
Non-recurring \| Impaired loans \| Maximum \| Discount cash flow \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Discount rate	18.25%	18.25%
Cash flows	$ 852,000	$ 861,000
Non-recurring \| Capitalized servicing rights \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Capitalized servicing rights	$ 3,393,000	$ 5,000
Non-recurring \| Capitalized servicing rights \| Maximum \| Discount cash flow \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Discount rate	7.55%	7.55%
Constant prepayment rate (CPR)	14.33%	17.09%
Non-recurring \| Other real estate owned \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Other real estate owned	$ 363,000	$ 90,000
Non-recurring \| Other real estate owned \| Fair value of collateral - appraised value \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Appraised value		$ 120,000
Non-recurring \| Other real estate owned \| Minimum \| Fair value of collateral - appraised value \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Appraised value	120,000
Non-recurring \| Other real estate owned \| Maximum \| Fair value of collateral - appraised value \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Appraised value	$ 215,000

Represents the appraised value used as an input to measure fair value.

No definition available.

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- Definition

Fair Value Inputs, Cash Flow

+ References

No definition available.

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- Definition

Represents the amount of impaired loans assets reported on the balance sheet at period end measured at fair value by the entity.

+ References

No definition available.

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
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- Definition

Loss, including interest and principal, incurred on a defaulted security, expressed as a percentage of the original principal balance, used as an input to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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- Definition

Rate at which loans or a loan portfolio are expected to prepay principal balances, used as an input to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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- Definition

Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 10
-Section S99
-Paragraph 6
-Subparagraph (SX 210.5-04(c)(Schedule III))
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- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
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