FAIR VALUE MEASUREMENT AND DISCLOSURE (Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financial assets:
Trading securities	$ 4,123	$ 4,161
Available-for-sale Securities	1,115,548	1,115,813
Loans held for sale	22,243	40,499
Financial liabilities:
Debt Securities, Trading	4,123	4,161
Obligations of U.S. government sponsored enterprises
Financial assets:
Available-for-sale Securities	4,983
Obligations of states and political subdivisions
Financial assets:
Available-for-sale Securities	119,799	127,120
Mortgage-backed securities issued or guaranteed by U.S. government-sponsored enterprises
Financial assets:
Available-for-sale Securities	569,319	566,618
Collateralized mortgage obligations issued or guaranteed by U.S. government-sponsored enterprises
Financial assets:
Available-for-sale Securities	410,644	410,454
Fair Value, Measurements, Recurring
Financial assets:
Trading securities	4,123	4,161
Loans held for sale	22,229	41,557
Financial liabilities:
Debt Securities, Trading	4,123	4,161
Fair Value, Measurements, Recurring | Obligations of U.S. government sponsored enterprises
Financial assets:
Available-for-sale Securities	4,983
Fair Value, Measurements, Recurring | Obligations of states and political subdivisions
Financial assets:
Available-for-sale Securities	119,799	127,120
Fair Value, Measurements, Recurring | Mortgage-backed securities issued or guaranteed by U.S. government-sponsored enterprises
Financial assets:
Available-for-sale Securities	569,319	566,618
Fair Value, Measurements, Recurring | Collateralized mortgage obligations issued or guaranteed by U.S. government-sponsored enterprises
Financial assets:
Available-for-sale Securities	410,644	410,454
Fair Value, Measurements, Recurring | Corporate Bond Securities [Member]
Financial assets:
Available-for-sale Securities	10,803	11,621
Readily Available Market Prices (Level 1) | Fair Value, Measurements, Recurring
Financial assets:
Trading securities	4,123	4,161
Loans held for sale	0	0
Financial liabilities:
Debt Securities, Trading	4,123	4,161
Readily Available Market Prices (Level 1) | Fair Value, Measurements, Recurring | Obligations of U.S. government sponsored enterprises
Financial assets:
Available-for-sale Securities	0
Readily Available Market Prices (Level 1) | Fair Value, Measurements, Recurring | Obligations of states and political subdivisions
Financial assets:
Available-for-sale Securities	0	0
Readily Available Market Prices (Level 1) | Fair Value, Measurements, Recurring | Mortgage-backed securities issued or guaranteed by U.S. government-sponsored enterprises
Financial assets:
Available-for-sale Securities	0	0
Readily Available Market Prices (Level 1) | Fair Value, Measurements, Recurring | Collateralized mortgage obligations issued or guaranteed by U.S. government-sponsored enterprises
Financial assets:
Available-for-sale Securities	0	0
Readily Available Market Prices (Level 1) | Fair Value, Measurements, Recurring | Corporate Bond Securities [Member]
Financial assets:
Available-for-sale Securities	0	0
Observable Market Data (Level 2) | Fair Value, Measurements, Recurring
Financial assets:
Trading securities	0	0
Loans held for sale	22,229	41,557
Financial liabilities:
Debt Securities, Trading	0	0
Observable Market Data (Level 2) | Fair Value, Measurements, Recurring | Obligations of U.S. government sponsored enterprises
Financial assets:
Available-for-sale Securities	4,983
Observable Market Data (Level 2) | Fair Value, Measurements, Recurring | Obligations of states and political subdivisions
Financial assets:
Available-for-sale Securities	119,799	127,120
Observable Market Data (Level 2) | Fair Value, Measurements, Recurring | Mortgage-backed securities issued or guaranteed by U.S. government-sponsored enterprises
Financial assets:
Available-for-sale Securities	569,319	566,618
Observable Market Data (Level 2) | Fair Value, Measurements, Recurring | Collateralized mortgage obligations issued or guaranteed by U.S. government-sponsored enterprises
Financial assets:
Available-for-sale Securities	410,644	410,454
Observable Market Data (Level 2) | Fair Value, Measurements, Recurring | Corporate Bond Securities [Member]
Financial assets:
Available-for-sale Securities	10,803	11,621
Company Determined Fair Value (Level 3) | Fair Value, Measurements, Recurring
Financial assets:
Trading securities	0	0
Loans held for sale	0	0
Financial liabilities:
Debt Securities, Trading	0	0
Company Determined Fair Value (Level 3) | Fair Value, Measurements, Recurring | Obligations of U.S. government sponsored enterprises
Financial assets:
Available-for-sale Securities	0
Company Determined Fair Value (Level 3) | Fair Value, Measurements, Recurring | Obligations of states and political subdivisions
Financial assets:
Available-for-sale Securities	0	0
Company Determined Fair Value (Level 3) | Fair Value, Measurements, Recurring | Mortgage-backed securities issued or guaranteed by U.S. government-sponsored enterprises
Financial assets:
Available-for-sale Securities	0	0
Company Determined Fair Value (Level 3) | Fair Value, Measurements, Recurring | Collateralized mortgage obligations issued or guaranteed by U.S. government-sponsored enterprises
Financial assets:
Available-for-sale Securities	0	0
Company Determined Fair Value (Level 3) | Fair Value, Measurements, Recurring | Corporate Bond Securities [Member]
Financial assets:
Available-for-sale Securities	0	0
Interest Rate Lock Commitments [Member] | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	1,465	608
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	160	248
Interest Rate Lock Commitments [Member] | Readily Available Market Prices (Level 1) | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	0	0
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value		0
Interest Rate Lock Commitments [Member] | Observable Market Data (Level 2) | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	1,465	608
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	160	248
Interest Rate Lock Commitments [Member] | Company Determined Fair Value (Level 3) | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	0	0
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	0	0
Forward delivery commitments | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	607	311
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	10	196
Forward delivery commitments | Readily Available Market Prices (Level 1) | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	0	0
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value		0
Forward delivery commitments | Observable Market Data (Level 2) | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	607	311
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	10	196
Forward delivery commitments | Company Determined Fair Value (Level 3) | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	0	0
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	0	0
Customer loan swaps | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	25,164	39,627
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	25,164	39,627
Customer loan swaps | Readily Available Market Prices (Level 1) | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	0	0
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	0	0
Customer loan swaps | Observable Market Data (Level 2) | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	25,164	39,627
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	25,164	39,627
Customer loan swaps | Company Determined Fair Value (Level 3) | Fair Value, Measurements, Recurring
Financial assets:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	0	0
Financial liabilities:
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	0	0
Interest rate contracts
Financial assets:
Fair Value	9,188	5,731
Financial liabilities:
Derivative Liability	8,520	11,625
Interest rate contracts | Fair Value, Measurements, Recurring
Financial assets:
Fair Value	9,188	5,731
Financial liabilities:
Derivative Liability	8,520	11,625
Interest rate contracts | Readily Available Market Prices (Level 1) | Fair Value, Measurements, Recurring
Financial assets:
Fair Value	0	0
Financial liabilities:
Derivative Liability		0
Interest rate contracts | Observable Market Data (Level 2) | Fair Value, Measurements, Recurring
Financial assets:
Fair Value	9,188	5,731
Financial liabilities:
Derivative Liability	8,520	11,625
Interest rate contracts | Company Determined Fair Value (Level 3) | Fair Value, Measurements, Recurring
Financial assets:
Fair Value	0	0
Financial liabilities:
Derivative Liability	$ 0	$ 0