SECURITIES (Summary of Amortized Costs and Estimated Fair Values of Available-For-Sale Securities) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	$ 806,685	$ 820,728
Available-for-sale, Unrealized Gains	7,586	7,525
Available-for-sale, Unrealized Losses	(17,029)	(19,776)
Available-for-sale, Fair Value	797,242	808,477
Held-to-maturity Securities	6,973	0
Held to Maturity Securities Gross Unrealized Gain Accumulated in Investments	29
Held to Maturity Securities Gross Unrealized Loss Accumulated in Investments	(35)
Held-to-maturity Securities, Fair Value	6,967
US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	4,956
Available-for-sale, Unrealized Gains	6
Available-for-sale, Unrealized Losses	0
Available-for-sale, Fair Value	4,962
Obligations of states and political subdivisions
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	28,681	30,143
Available-for-sale, Unrealized Gains	995	1,075
Available-for-sale, Unrealized Losses	(2)	(11)
Available-for-sale, Fair Value	29,674	31,207
Held-to-maturity Securities	6,973
Held to Maturity Securities Gross Unrealized Gain Accumulated in Investments	29
Held to Maturity Securities Gross Unrealized Loss Accumulated in Investments	(35)
Held-to-maturity Securities, Fair Value	6,967
Mortgage-backed securities issued or guaranteed by U.S. government sponsored enterprises
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	394,010	397,409
Available-for-sale, Unrealized Gains	5,793	5,528
Available-for-sale, Unrealized Losses	(5,040)	(7,034)
Available-for-sale, Fair Value	394,763	395,903
Collateralized mortgage obligations issued or guaranteed by U.S. government sponsored enterprises
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	372,200	385,847
Available-for-sale, Unrealized Gains	752	912
Available-for-sale, Unrealized Losses	(11,613)	(12,324)
Available-for-sale, Fair Value	361,339	374,435
Private issue collateralized mortgage obligations
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	6,838	7,329
Available-for-sale, Unrealized Gains	40	10
Available-for-sale, Unrealized Losses	(374)	(407)
Available-for-sale, Fair Value	$ 6,504	$ 6,932