FAIR VALUE MEASUREMENTS - Unobservable Inputs Non-recurring (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Other real estate owned	$ 2,205	$ 2,236
Non-recurring \| Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Impaired loans	8,335	9,625
Capitalized servicing rights	3,897	4,301
Other real estate owned	2,205	2,236
Carrying value of assets held for sale	1,764	1,764
Total	16,201	17,926
Non-recurring \| Level 3 \| Fair value of collateral -appraised value
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Impaired loans	4,947	6,137
Non-recurring \| Level 3 \| Discount cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Impaired loans	$ 3,388	$ 3,488
Non-recurring \| Level 3 \| Impaired loans \| Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Loss severity	0.00%	0.00%
Appraised value	$ 0	$ 0
Cash flows	$ 21	$ 22
Discount rate	3.50%	2.88%
Non-recurring \| Level 3 \| Impaired loans \| Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Loss severity	70.00%	55.00%
Appraised value	$ 975	$ 6,915
Cash flows	$ 1,002	$ 1,002
Discount rate	9.50%	9.50%
Non-recurring \| Level 3 \| Capitalized servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Constant prepayment rate (CPR)	11.91%	9.95%
Discount rate	11.33%	10.07%
Non-recurring \| Level 3 \| Other real estate owned
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Appraised value	$ 2,695	$ 2,695
Non-recurring \| Level 3 \| Other real estate owned \| Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Selling Costs	6.00%	10.00%
Non-recurring \| Level 3 \| Other real estate owned \| Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Selling Costs	10.00%	20.00%
Non-recurring \| Level 3 \| Assets held for sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Carrying value of assets held for sale	$ 1,764	$ 1,764
Selling Costs	6.00%	6.00%
Non-recurring \| Level 3 \| Assets held for sale \| Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Appraised value	$ 136	$ 136
Non-recurring \| Level 3 \| Assets held for sale \| Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items}
Appraised value	$ 527	$ 527

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- Definition

Fair Value Inputs, Cash Flow

+ References

No definition available.

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- Definition

Fair Value Inputs, Selling Costs

+ 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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Fair value portion of assets classified as held for sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&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

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
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5162-111524

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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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745

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-SubTopic 50
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- Definition

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

+ References

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-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 2
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- Definition

Percentage of contractually collectible principal associated with a financial asset expected not to be collected due to default by the borrower.

+ References

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- Definition

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

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