INVESTMENT SECURITIES (Tables)

12 Months Ended

Dec. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Unrealized Gain (Loss) on Investments [Table Text Block]

The amortized cost, related estimated fair value, and unrealized gains and losses for investment securities classified as “Available-For-Sale” or “Held-to-Maturity” were as follows at December 31, 2016 and 2015:

	Available-for-Sale Securities
(Dollars in thousands)			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
December 31, 2016:
U.S. Treasury securities	$	1,008	$	2	$	—	$	1,010
Obligations of U.S. Government Corporations and Agencies:
Mortgage-backed		112,155		83		(1,331)		110,907
Other		21,399		82		(511)		20,970
Obligations of state and political subdivisions		211,154		2,776		(2,796)		211,134
Corporate debt securities		35,178		4		(1,206)		33,976
Marketable equity securities		810		830		—		1,640
Total	$	381,704	$	3,777	$	(5,844)	$	379,637

	Held-to-Maturity Securities
(Dollars in thousands)			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
December 31, 2016:
Obligations of U.S. Government Corporations and Agencies:
Mortgage-backed	$	4	$	—	$	—	$	4
Total	$	4	$	—	$	—	$	4

	Available-for-Sale Securities
(Dollars in thousands)			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
December 31, 2015:
U.S. Treasury securities	$	1,022	$	—	$	(1)	$	1,021
Obligations of U.S. Government Corporations and Agencies:
Mortgage-backed		113,847		37		(1,410)		112,474
Other		21,554		117		(79)		21,592
Obligations of state and political subdivisions		195,297		5,425		(408)		200,314
Corporate debt securities		49,162		10		(1,339)		47,833
Marketable equity securities		1,194		813		—		2,007
Total	$	382,076	$	6,402	$	(3,237)	$	385,241

	Held-to-Maturity Securities
(Dollars in thousands)			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
December 31, 2015:
Obligations of U.S. Government Corporations and Agencies:
Mortgage-backed	$	26	$	1	$	—	$	27
Total	$	26	$	1	$	—	$	27

Investments Classified by Contractual Maturity Date [Table Text Block]

The amortized cost and fair value of securities, by contractual maturity, are shown below at December 31, 2016. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.

(Dollars in thousands)	Available for Sale				Held to Maturity
	Amortized				Amortized
	Cost		Fair Value		Cost		Fair Value
1 year or less	$	2,264	$	2,264	$	—	$	—
Over 1 year through 5 years		59,860		60,118		—		—
Over 5 years through 10 years		97,209		95,887		—		—
Over 10 years		109,406		108,821		—		—
Mortgage-backed securities		112,155		110,907		4		4
Marketable equity securities		810		1,640		—		—
	$	381,704	$	379,637	$	4	$	4

Schedule of Unrealized Loss on Investments [Table Text Block]

In accordance with disclosures required by FASB ASC 320-10-50, Investments - Debt and Equity Securities, the summary below shows the gross unrealized losses and fair value of the Corporation’s investments, aggregated by investment category, that individual securities have been in a continuous unrealized loss position for less than 12 months or 12 months or more as of December 31, 2016 and 2015:

December 31, 2016
(Dollars in thousands)	Less Than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Loss		Value		Loss		Value		Loss
Available-for-Sale:
U.S. Treasury securities	$	—	$	—	$	—	$	—	$	—	$	—
Obligations of U.S. Government Corporations and Agencies:
Mortgage-backed		89,444		(1,216)		8,783		(115)		98,227		(1,331)
Other		10,340		(500)		1,741		(11)		12,081		(511)
Obligations of state and political subdivisions		95,481		(2,796)		—		—		95,481		(2,796)
Corporate debt securities		21,656		(749)		10,298		(457)		31,954		(1,206)
Marketable equity securities		—		—		—		—		—		—
	$	216,921	$	(5,261)	$	20,822	$	(583)	$	237,743	$	(5,844)

December 31, 2015
(Dollars in thousands)	Less Than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Loss		Value		Loss		Value		Loss
Available-for-Sale:								—
U.S. Treasury securities	$	1,021	$	(1)	$	—	$	—	$	1,021	$	(1)
Obligations of U.S. Government Corporations and Agencies:
Mortgage-backed		86,618		(1,177)		11,234		(233)		97,852		(1,410)
Other		12,962		(79)		—		—		12,962		(79)
Obligations of state and political subdivisions		26,163		(258)		8,105		(150)		34,268		(408)
Corporate debt securities		27,527		(531)		19,433		(808)		46,960		(1,339)
Marketable equity securities		—		—		—		—		—		—
	$	154,291	$	(2,046)	$	38,772	$	(1,191)	$	193,063	$	(3,237)