COMMITMENTS, CONTINGENCIES AND DERIVATIVES (Summary of Contractual and Notional Amounts of Financial Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Customer Loan Swaps
Financial Instruments [Line Items]
Notional amount of derivative	$ 802,580	$ 833,030
Forward-Starting Interest Rate Swap
Financial Instruments [Line Items]
Notional amount of derivative	0	25,000
Interest rate swaps
Financial Instruments [Line Items]
Notional amount of derivative	43,000	43,000
Interest rate lock commitments
Financial Instruments [Line Items]
Notional amount of derivative	22,840	12,077
Forward Contracts [Member]
Financial Instruments [Line Items]
Notional amount of derivative	8,711	4,315
Standby Letters of Credit [Member]
Financial Instruments [Line Items]
Contractual Amounts Of Financial Instrument	5,938	3,063
Commitments to Extend Credit [Member]
Financial Instruments [Line Items]
Contractual Amounts Of Financial Instrument	$ 669,193	$ 654,575