INVESTMENT SECURITIES (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 822,699	$ 778,261	$ 858,010
Gross Unrealized Gains	21,201	8,136	8,437
Gross Unrealized Losses	(254)	(3,212)	(4,293)
Fair Value	843,646	783,185	862,154
U.S. government sponsored agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,999	14,959	14,956
Gross Unrealized Gains	38	0	0
Gross Unrealized Losses	0	(69)	(210)
Fair Value	6,037	14,890	14,746
State, county and municipal securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	151,504	157,681	165,070
Gross Unrealized Gains	6,936	4,046	3,305
Gross Unrealized Losses	(54)	(411)	(1,003)
Fair Value	158,386	161,316	167,372
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	20,151	5,900	12,710
Gross Unrealized Gains	174	145	184
Gross Unrealized Losses	(22)	(28)	(58)
Fair Value	20,303	6,017	12,836
Mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	645,045	599,721	665,274
Gross Unrealized Gains	14,053	3,945	4,948
Gross Unrealized Losses	(178)	(2,704)	(3,022)
Fair Value	$ 658,920	$ 600,962	$ 667,200