COMMITMENTS, CONTINGENCIES AND DERIVATIVES (Summary of Contractual and Notional Amounts of Financial Instruments) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Customer Loan Swaps
Financial Instruments [Line Items]
Notional amount of derivative	$ 728,226	$ 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	27,736	21,746
Forward Contracts [Member]
Financial Instruments [Line Items]
Notional amount of derivative	12,585	8,065
Other Commitments
Financial Instruments [Line Items]
Notional amount of derivative	2,327	523
Letters of Credit
Financial Instruments [Line Items]
Notional amount of derivative	3,009	2,848
Home Equity
Financial Instruments [Line Items]
Notional amount of derivative	499,559	477,401
Commercial and commercial real estate
Financial Instruments [Line Items]
Notional amount of derivative	35,205	49,482
Residential
Financial Instruments [Line Items]
Notional amount of derivative	$ 47,554	$ 41,368