FAIR VALUE MEASUREMENTS - Unobservable Inputs Non-recurring (Details) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Quantitative information about the significant unobservable inputs within Level 3
Other real estate owned	$ 2,351,000	$ 122,000
Non-recurring \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Total	22,446,000	15,073,000
Non-recurring \| Fair value of collateral - appraised value \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Impaired loans	11,676,000	8,586,000
Other real estate owned	2,351,000	122,000
Non-recurring \| Discounted cash flow \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Impaired loans	3,537,000	2,207,000
Capitalized servicing rights	4,882,000	4,158,000
Non-recurring \| Impaired loans \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Impaired loans	15,213,000	10,793,000
Non-recurring \| Impaired loans \| Minimum \| Fair value of collateral - appraised value \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Appraised value	$ 0	$ 100,000
Non-recurring \| Impaired loans \| Minimum \| Discounted cash flow \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Discount rate	2.88%	2.63%
Cash flows	$ 22,000	$ 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
Appraised value	$ 6,915,000	$ 7,545,000
Non-recurring \| Impaired loans \| Maximum \| Discounted cash flow \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Discount rate	9.50%	9.50%
Cash flows	$ 1,072,000	$ 320,000
Non-recurring \| Capitalized servicing rights \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Capitalized servicing rights	4,882,000	4,158,000
Non-recurring \| Other real estate owned \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Other real estate owned	2,351,000	122,000
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	$ 2,700,000	$ 136,000
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Selling Costs	12.93%
Measurement Input, Constant Prepayment Rate \| Non-recurring \| Capitalized servicing rights \| Discounted cash flow \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Constant prepayment rate (CPR)		10.97%
Measurement Input, Discount Rate \| Non-recurring \| Capitalized servicing rights \| Discounted cash flow \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Discount rate	10.08%	10.10%
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Selling Costs		10.00%
Measurement Input, Prepayment Rate \| Non-recurring \| Capitalized servicing rights \| Discounted cash flow \| Level 3
Quantitative information about the significant unobservable inputs within Level 3
Constant prepayment rate (CPR)	8.19%
Measurement Input, Loss Severity \| 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%	15.70%
Measurement Input, Loss Severity \| 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	55.00%	45.28%

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- Definition

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+ 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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Other Than Temporary Impairment Losses, Investments, Impaired Loans, Portion Recognized in Earnings, Net, Qualitative Disclosures, Loan to Collateral Value

+ References

No definition available.

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+ 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.

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-Publisher FASB
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+ References

No definition available.

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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/disclosureRef
-Publisher FASB
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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/disclosureRef
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- Definition

Discount rate used to estimate the fair value of servicing assets and servicing liabilities.

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- Definition

Estimated rate of prepayments of principal on servicing assets and servicing liabilities.

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