NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	12 Months Ended
Dec. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Number of reportable segments \| segment	1
Credit losses related to unfunded loan commitments	$ 11,385,000	$ 9,836,000	$ 9,309,000
Threshold amount of estimate loss for evaluating individual loans for impairment	100,000
Accrued interest related to unrecognized tax benefits	0
Fair value of trust assets under management	$ 1,103,228,000	1,007,113,000
Trust revenue is earned and collected monthly	83.00%
Commercial
Credit losses related to unfunded loan commitments	$ 6,308,000	4,788,000	4,591,000
Commercial \| Maximum
Threshold amount of loan balance for evaluating individual impairment loss	200,000
Residential mortgage
Credit losses related to unfunded loan commitments	4,253,000	4,182,000	3,986,000
Residential mortgage \| Maximum
Threshold amount of loan balance for evaluating individual impairment loss	400,000
Consumer
Credit losses related to unfunded loan commitments	239,000	281,000	$ 233,000
Consumer \| Maximum
Threshold amount of loan balance for evaluating individual impairment loss	400,000
Unfunded Loan Commitment
Credit losses related to unfunded loan commitments	$ 0	$ 0

The fair value of trust assets under management.

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- Definition

The amount of estimated loss on a financing receivable with relationships less than $200,000 in the aggregate which will trigger that financing receivable to be individually evaluated for impairment.

+ References

No definition available.

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Threshold for determining if a financing receivable with an estimated loss of $100,000 or more, will be individually evaluated for impairment.

+ References

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- Definition

The percent of trust revenue earned and collected monthly.

+ References

No definition available.

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- Definition

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Amount of interest expense accrued for an underpayment of income taxes.

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