SECURITIES (Schedule of Amortized Cost and Estimated Fair Values of Debt Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Available-for-sale, Amortized Cost
Due in one year or less	$ 3,594
Due after one year through five years	87,212
Due after five years through ten years	110,852
Due after ten years	518,149
Amortized cost, total	719,807
Available-for-sale, Fair Value
Due in one year or less	3,634
Due after one year through five years	88,411
Due after five years through ten years	113,415
Due after ten years	518,777
Fair value, total	724,237
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis [Abstract]
Due in one year or less	0
Due after one year through five years	2,234
Due after five years through ten years	1,134
Due after ten years	72,000
Held-to-maturity securities, at amortized cost	75,368	$ 20,179
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Fair Value [Abstract]
Due in one year or less	0
Due after one year through five years	2,290
Due after five years through ten years	1,143
Due after ten years	73,145
Held-to-maturity Securities, Fair Value	$ 76,578	$ 20,425