SECURITIES - Amortized Cost and Fair Value of Securities Available for Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available for sale securities
Amortized Cost	$ 1,071,107	$ 1,002,803
Gross Unrealized Gains	14,150	13,641
Gross Unrealized Losses	(7,684)	(8,904)
Fair Value	1,077,573	1,007,540
U. S. government agency
Available for sale securities
Amortized Cost	114	951
Gross Unrealized Gains	1	4
Fair Value	115	955
State and municipal
Available for sale securities
Amortized Cost	385,844	361,335
Gross Unrealized Gains	12,724	10,799
Gross Unrealized Losses	(442)	(2,848)
Fair Value	398,126	369,286
Mortgage-backed securities-residential (Government Sponsored Entity)
Available for sale securities
Amortized Cost	386,116	450,006
Gross Unrealized Gains	930	1,253
Gross Unrealized Losses	(3,792)	(4,629)
Fair Value	383,254	446,630
Collateralized mortgage obligations (Government Sponsored Entity)
Available for sale securities
Amortized Cost	289,425	179,314
Gross Unrealized Gains	420	1,514
Gross Unrealized Losses	(3,450)	(1,427)
Fair Value	286,395	179,401
Equity securities
Available for sale securities
Amortized Cost	4,670	4,670
Fair Value	4,670	4,670
Other securities
Available for sale securities
Amortized Cost	4,938	6,527
Gross Unrealized Gains	75	71
Fair Value	$ 5,013	$ 6,598

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65884222&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 45
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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
-Paragraph 2
-Subparagraph (c)
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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
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