FAIR VALUE - Significant Unobservable Inputs (Details)	12 Months Ended
Dec. 31, 2020 USD ($)	Jun. 30, 2021 USD ($)
Minimum [Member] \| Fair Value of Collateral [Member] \| Estimated Cost of Disposal/Market Adjustment [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Other real estate owned, measurement input		9.0
Maximum [Member] \| Fair Value of Collateral [Member] \| Estimated Cost of Disposal/Market Adjustment [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Other real estate owned, measurement input		51.1
Significant Unobservable Inputs, Level 3 [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Impaired loans	$ 25,063,000	$ 21,330,000
Other real estate owned	883,000	879,000
Fair value of MSRs at end of period	$ 682,000	$ 697,000
Significant Unobservable Inputs, Level 3 [Member] \| Fair Value of Collateral [Member] \| Estimated Cost of Disposal/Market Adjustment [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Impaired loans, Valuation Technique [Extensible List]	Fair Value of Collateral [Member]	Fair Value of Collateral [Member]
Impaired loans, Measurement Input [Extensible List]	us-gaap:MeasurementInputCostToSellMember	us-gaap:MeasurementInputCostToSellMember
Other real estate owned, Valuation Technique [Extensible List]	Fair Value of Collateral [Member]	Fair Value of Collateral [Member]
Other real estate owned, Measurement Input [Extensible List]	us-gaap:MeasurementInputCostToSellMember	us-gaap:MeasurementInputCostToSellMember
Significant Unobservable Inputs, Level 3 [Member] \| Discounted Cash Flow [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, Valuation Technique [Extensible List]	Discounted Cash Flow [Member]	Discounted Cash Flow [Member]
Significant Unobservable Inputs, Level 3 [Member] \| Discounted Cash Flow [Member] \| Weighted Average Constant Prepayment Rate [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, Measurement Input [Extensible List]	Weighted Average Constant Prepayment Rate [Member]	Weighted Average Constant Prepayment Rate [Member]
Significant Unobservable Inputs, Level 3 [Member] \| Discounted Cash Flow [Member] \| Weighted Average Discount Rate [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, Measurement Input [Extensible List]	Weighted Average Discount Rate [Member]	Weighted Average Discount Rate [Member]
Significant Unobservable Inputs, Level 3 [Member] \| Discounted Cash Flow [Member] \| Adequate Compensation [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, measurement input		7
Mortgage servicing rights, measurement input	7
Mortgage servicing rights, Measurement Input [Extensible List]	Adequate Compensation [Member]	Adequate Compensation [Member]
Significant Unobservable Inputs, Level 3 [Member] \| Minimum [Member] \| Fair Value of Collateral [Member] \| Estimated Cost of Disposal/Market Adjustment [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Impaired loans, measurement input	9.0	9.0
Other real estate owned, measurement input	11.3	9.0
Significant Unobservable Inputs, Level 3 [Member] \| Minimum [Member] \| Discounted Cash Flow [Member] \| Weighted Average Constant Prepayment Rate [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, measurement input	9.8	16.9
Significant Unobservable Inputs, Level 3 [Member] \| Minimum [Member] \| Discounted Cash Flow [Member] \| Weighted Average Discount Rate [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, measurement input	1.7	2.2
Significant Unobservable Inputs, Level 3 [Member] \| Maximum [Member] \| Fair Value of Collateral [Member] \| Estimated Cost of Disposal/Market Adjustment [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Impaired loans, measurement input	78.4	78.7
Other real estate owned, measurement input	52.9	51.1
Significant Unobservable Inputs, Level 3 [Member] \| Maximum [Member] \| Discounted Cash Flow [Member] \| Weighted Average Constant Prepayment Rate [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, measurement input	18.8	49.1
Significant Unobservable Inputs, Level 3 [Member] \| Maximum [Member] \| Discounted Cash Flow [Member] \| Weighted Average Discount Rate [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, measurement input	2.2	2.8
Significant Unobservable Inputs, Level 3 [Member] \| Weighted Average [Member] \| Fair Value of Collateral [Member] \| Estimated Cost of Disposal/Market Adjustment [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Impaired loans, measurement input	52.7	53.8
Other real estate owned, measurement input	34.0	34.5
Significant Unobservable Inputs, Level 3 [Member] \| Weighted Average [Member] \| Discounted Cash Flow [Member] \| Weighted Average Constant Prepayment Rate [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, measurement input	17.6	21.8
Significant Unobservable Inputs, Level 3 [Member] \| Weighted Average [Member] \| Discounted Cash Flow [Member] \| Weighted Average Discount Rate [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, measurement input	2.1	2.7
Commitments to originate real estate loans for sale \| Significant Unobservable Inputs, Level 3 [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Commitments to originate real estate loans for sale	$ 14,000	$ 130,000
Commitments to originate real estate loans for sale \| Significant Unobservable Inputs, Level 3 [Member] \| Discounted Cash Flow [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Commitments to originate real estate loans for sale, Valuation Technique [Extensible List]	Discounted Cash Flow [Member]	Discounted Cash Flow [Member]
Commitments to originate real estate loans for sale, measurement input	1.0	1.0
Commitments to originate real estate loans for sale \| Significant Unobservable Inputs, Level 3 [Member] \| Discounted Cash Flow [Member] \| Embedded Servicing Value [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Commitments to originate real estate loans for sale, Measurement Input [Extensible List]	Embedded Servicing Value [Member]	Embedded Servicing Value [Member]

This is the amount of impaired loans carried at fair value.

No definition available.

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Value of input used to measure impaired loans.

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Value of input used to measure derivative asset.

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Indicates measurement input for derivative asset.

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Indicates valuation technique for measuring derivative asset.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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- Definition

Indicates measurement input for loan held for sale.

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Indicates valuation technique for measuring loan held for sale.

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- Definition

Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure.

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Value of input used to measure real estate owned by financial institution by financial institution which is not directly related to its business.

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- Definition

Fair value of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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Value of input used to measure servicing asset.

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