SECURITIES (Summary of Amortized Costs and Estimated Fair Values of Available-For-Sale Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	$ 788,224	$ 756,186
Available-for-sale, Unrealized Gains	12,771	4,293
Available-for-sale, Unrealized Losses	(1,469)	(10,141)
Available-for-sale, Fair Value	799,526	750,338
Held-to-maturity securities, at amortized cost	93,609	84,144
Held-to-maturity securities, Unrealized Gains	4,086	1,564
Held-to-maturity securities, Unrealized Losses	(3)	(61)
Held-to-maturity Securities, Fair Value	97,692	85,647
Obligations of U.S. government-sponsored enterprises
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	4,975	4,971
Available-for-sale, Unrealized Gains	156	69
Available-for-sale, Unrealized Losses	0	0
Available-for-sale, Fair Value	5,131	5,040
Obligations of states and political subdivisions
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	9,765	17,355
Available-for-sale, Unrealized Gains	279	339
Available-for-sale, Unrealized Losses	0	0
Available-for-sale, Fair Value	10,044	17,694
Held-to-maturity securities, at amortized cost	93,609	84,144
Held-to-maturity securities, Unrealized Gains	4,086	1,564
Held-to-maturity securities, Unrealized Losses	(3)	(61)
Held-to-maturity Securities, Fair Value	97,692	85,647
Mortgage-backed securities issued or guaranteed by U.S. government-sponsored enterprises
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	461,493	419,429
Available-for-sale, Unrealized Gains	9,117	3,474
Available-for-sale, Unrealized Losses	(139)	(3,857)
Available-for-sale, Fair Value	470,471	419,046
Collateralized mortgage obligations issued or guaranteed by U.S. government-sponsored enterprises
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	305,878	312,719
Available-for-sale, Unrealized Gains	3,064	409
Available-for-sale, Unrealized Losses	(1,330)	(6,271)
Available-for-sale, Fair Value	307,612	306,857
Corporate Debt Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	5,481	1,000
Available-for-sale, Unrealized Gains	142	0
Available-for-sale, Unrealized Losses	0	(4)
Available-for-sale, Fair Value	5,623	996
Debt Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	787,592	755,474
Available-for-sale, Unrealized Gains	12,758	4,291
Available-for-sale, Unrealized Losses	(1,469)	(10,132)
Available-for-sale, Fair Value	798,881	749,633
Equity Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale, Amortized Cost	632	712
Available-for-sale, Unrealized Gains	13	2
Available-for-sale, Unrealized Losses	0	(9)
Available-for-sale, Fair Value	$ 645	$ 705

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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