Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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Average remaining period until maturity of the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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.

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Nominal or face amount used to calculate payment on derivative.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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Amount of asset hedged in fair value hedging relationship.

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Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk.

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DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Apr. 30, 2020	Dec. 31, 2019	Nov. 30, 2019
Derivative [Line Items]
Notional Amount	$ 929,882	$ 876,603
Fair Value Asset (Liability)	(2,223)	(5,526)
Interest rate swap on deposits
Derivative [Line Items]
Notional Amount			$ 25,000		$ 50,000
Designated as hedging instrument \| Cash flow hedges
Derivative [Line Items]
Notional Amount	125,000	75,000
Fair Value Asset (Liability)	(1,289)	(2,664)
Designated as hedging instrument \| Cash flow hedges \| Interest rate cap agreements
Derivative [Line Items]
Notional Amount	$ 75,000	$ 75,000
Weighted Average Maturity (in years)	3 years 3 months 18 days	4 years
Fair Value Asset (Liability)	$ (1,168)	$ (2,664)
Designated as hedging instrument \| Cash flow hedges \| Interest rate swap on variable rate loans
Derivative [Line Items]
Notional Amount	$ 50,000
Weighted Average Maturity (in years)	4 years 6 months
Fair Value Asset (Liability)	$ (121)
Designated as hedging instrument \| Fair value hedges
Derivative [Line Items]
Notional Amount	37,190	37,190
Fair Value Asset (Liability)	(841)	(2,789)
Designated as hedging instrument \| Fair value hedges \| Interest rate swap on deposits
Derivative [Line Items]
Notional Amount	$ 37,190	$ 37,190		$ 37,200
Weighted Average Maturity (in years)	7 years 9 months 18 days	8 years 7 months 6 days
Fair Value Asset (Liability)	$ (841)	$ (2,789)
Hedged Asset, Fair Value Hedge	39,200	40,209
Cumulative amount of fair value hedging adjustment in carrying amount	2,010	3,019
Designated as hedging instrument \| Economic hedges
Derivative [Line Items]
Notional Amount	754,807	761,093
Fair Value Asset (Liability)	(140)	(95)
Designated as hedging instrument \| Economic hedges \| Forward sale commitments
Derivative [Line Items]
Notional Amount	$ 14,533	$ 50,629
Weighted Average Maturity (in years)	1 month 6 days	2 months 12 days
Fair Value Asset (Liability)	$ (140)	$ (95)
Designated as hedging instrument \| Economic hedges \| Customer loan derivative liability \| MNA counterparty
Derivative [Line Items]
Notional Amount	$ 250,852	$ 235,947
Weighted Average Maturity (in years)	6 years 4 months 24 days	6 years 9 months 18 days
Fair Value Asset (Liability)	$ (10,258)	$ (15,938)
Designated as hedging instrument \| Economic hedges \| Customer loan derivative liability \| RPA counterparty
Derivative [Line Items]
Notional Amount	$ 119,285	$ 119,285
Weighted Average Maturity (in years)	7 years 1 month 6 days	7 years 10 months 24 days
Fair Value Asset (Liability)	$ (5,892)	$ (9,957)
Designated as hedging instrument \| Economic hedges \| Customer loan derivative liability \| Customer
Derivative [Line Items]
Notional Amount	$ 370,137	$ 355,232
Weighted Average Maturity (in years)	6 years 7 months 6 days	7 years 1 month 6 days
Fair Value Asset (Liability)	$ 16,150	$ 25,895
Not designated as hedging instrument
Derivative [Line Items]
Notional Amount	12,885	3,320
Fair Value Asset (Liability)	47	22
Not designated as hedging instrument \| Interest rate lock commitments
Derivative [Line Items]
Notional Amount	$ 12,885	$ 3,320
Weighted Average Maturity (in years)	1 month 6 days	1 month 6 days
Fair Value Asset (Liability)	$ 47	$ 22