SECURITIES (Schedule of Amortized Cost and Estimated Fair Values of Debt Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Available-for-sale, Amortized Cost
Due in one year or less	$ 1,430
Due after one year through five years	107,452
Due after five years through ten years	101,018
Due after ten years	577,692
Amortized cost, total	787,592
Available-for-sale, Fair Value
Due in one year or less	1,441
Due after one year through five years	109,501
Due after five years through ten years	104,203
Due after ten years	583,736
Fair value, total	798,881
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis [Abstract]
Due after one year through five years	2,189
Due after five years through ten years	4,587
Due after ten years	86,833
Held-to-maturity securities, at amortized cost	93,609	$ 84,144
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Fair Value [Abstract]
Due after one year through five years	2,247
Due after five years through ten years	4,726
Due after ten years	90,719
Held-to-maturity Securities, Fair Value	$ 97,692	$ 85,647