COMMITMENTS, CONTINGENCIES AND DERIVATIVES (Summary of Contractual and Notional Amounts of Financial Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Customer Loan Swaps
Financial Instruments [Line Items]
Notional amount of derivative	$ 708,316	$ 703,336
Forward-Starting Interest Rate Swap
Financial Instruments [Line Items]
Notional amount of derivative	25,000	50,000
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	24,753	21,746
Forward Contracts [Member]
Financial Instruments [Line Items]
Notional amount of derivative	9,502	8,065
Other Commitments
Financial Instruments [Line Items]
Notional amount of derivative	1,151	523
Letters of Credit
Financial Instruments [Line Items]
Notional amount of derivative	3,426	2,848
Home Equity
Financial Instruments [Line Items]
Notional amount of derivative	501,127	477,401
Commercial and commercial real estate
Financial Instruments [Line Items]
Notional amount of derivative	31,667	49,482
Residential
Financial Instruments [Line Items]
Notional amount of derivative	$ 36,352	$ 41,368