SECURITIES

We classify debt and equity securities as “held to maturity”, “available for sale” or “trading” according to management’s intent. The appropriate classification is determined at the time of purchase of each security and re-evaluated at each reporting date.

Securities held to maturity: Certain debt securities for which we have the positive intent and ability to hold to maturity are reported at cost, adjusted for amortization of premiums and accretion of discounts. There are no securities classified as held to maturity in the accompanying financial statements.

Securities available for sale: Securities not classified as "held to maturity" or as "trading" are classified as "available for sale." Securities classified as "available for sale" are those securities that we intend to hold for an indefinite period of time, but not necessarily to maturity. "Available for sale" securities are reported at estimated fair value net of unrealized gains or losses, which are adjusted for applicable income taxes and reported as a separate component of shareholders' equity.

Trading securities: There are no securities classified as "trading" in the accompanying financial statements.

Impairment assessment: Impairment exists when the fair value of a security is less than its cost. Cost includes adjustments made to the cost basis of a security for accretion, amortization and previous other-than-temporary impairments. We perform a quarterly assessment of the debt and equity securities in our investment portfolio that have an unrealized loss to determine whether the decline in the fair value of these securities below their cost is other-than-temporary. This determination requires significant judgment. Impairment is considered other-than-temporary when it becomes probable that we will be unable to recover the cost of an investment. This assessment takes into consideration factors such as the length of time and the extent to which the market values have been less than cost, the financial condition and near term prospects of the issuer including events specific to the issuer or industry, defaults or deferrals of scheduled interest, principal or dividend payments, external credit ratings and recent downgrades and our intent and ability to hold the security for a period of time sufficient to allow for a recovery in fair value. If a decline in fair value is judged to be other than temporary, the cost basis of the individual security is written down to fair value which then becomes the new cost basis. The amount of the write down is included in other-than-temporary impairment of securities in the consolidated statements of income. The new cost basis is not adjusted for subsequent recoveries in fair value, if any.

Realized gains and losses on sales of securities are recognized on the specific identification method. Amortization of premiums and accretion of discounts are computed using the interest method.

The amortized cost, unrealized gains, unrealized losses and estimated fair values of securities at December 31, 2017 and 2016, are summarized as follows:



	December 31, 2017
	Amortized		Unrealized
Dollars in thousands	Cost		Gains		Losses		Fair Value
Available for Sale
Taxable debt securities
U.S. Government and agencies and corporations	$	31,260	$	498	$	145	$	31,613
Residential mortgage-backed securities:
Government-sponsored agencies	120,948		1,276		903		121,321
Nongovernment-sponsored entities	2,045		39		7		2,077
State and political subdivisions
General obligations	6,090		—		55		6,035
Other revenues	11,657		47		62		11,642
Corporate debt securities	16,375		—		130		16,245
Total taxable debt securities	188,375		1,860		1,302		188,933
Tax-exempt debt securities
State and political subdivisions
General obligations	65,560		1,530		198		66,892
Water and sewer revenues	23,108		566		3		23,671
Lease revenues	13,024		451		2		13,473
Electric revenues	6,205		128		—		6,333
Sales tax revenues	4,126		140		—		4,266
University revenues	5,272		38		9		5,301
Other revenues	19,101		616		—		19,717
Total tax-exempt debt securities	136,396		3,469		212		139,653
Equity securities	137		—		—		137
Total available for sale securities	$	324,908	$	5,329	$	1,514	$	328,723



	December 31, 2016
	Amortized		Unrealized
Dollars in thousands	Cost		Gains		Losses		Fair Value
Available for Sale
Taxable debt securities
U.S. Government and agencies and corporations	$	14,580	$	642	$	48	$	15,174
Residential mortgage-backed securities:
Government-sponsored agencies	138,451		1,554		1,159		138,846
Nongovernment-sponsored entities	4,631		44		22		4,653
Corporate debt securities	18,295		23		148		18,170
Total taxable debt securities	175,957		2,263		1,377		176,843
Tax-exempt debt securities
State and political subdivisions
General obligations	49,449		569		1,388		48,630
Water and sewer revenues	9,087		63		149		9,001
Lease revenues	9,037		7		201		8,843
Electric revenues	3,247		10		48		3,209
Sales tax revenues	2,870		—		34		2,836
Other revenues	17,321		93		371		17,043
Total tax-exempt debt securities	91,011		742		2,191		89,562
Equity securities	137		—		—		137
Total available for sale securities	$	267,105	$	3,005	$	3,568	$	266,542

The below information is relative to the five states where issuers with the highest volume of state and political subdivision securities held in our portfolio are located. We own no such securities of any single issuer which we deem to be a concentration.



	December 31, 2017
	Amortized		Unrealized
Dollars in thousands	Cost		Gains		Losses		Fair Value

Texas	$	20,055	$	611	$	48	$	20,618
Michigan	19,362		292		94		19,560
California	12,265		411		21		12,655
Illinois	11,125		214		12		11,327
New York	10,732		298		18		11,012

Management performs pre-purchase and ongoing analysis to confirm that all investment securities meet applicable credit quality standards. We principally use credit ratings from Nationally Recognized Statistical Rating Organizations (“NRSROs”) to support analyses of our portfolio of securities issued by state and political subdivisions, as we generally do not purchase securities that are rated below the six highest NRSRO rating categories. In addition to considering a security’s NRSRO rating, we also assess or confirm through an internal review of an issuer’s financial information and other applicable information that: 1) the issuer’s risk of default is low; 2) the characteristics of the issuer’s demographics and economic environment are satisfactory; and 3) the issuer’s budgetary position and stability of tax or other revenue sources are sound.

The proceeds from sales, calls and maturities of available for sale securities, including principal payments received on mortgage-backed obligations, and the related gross gains and losses realized are as follows:



Dollars in thousands	Proceeds from						Gross realized
			Calls and		Principal
Years ended December 31,	Sales		Maturities		Payments		Gains		Losses
2017	$	152,882	$	2,700	$	31,902	$	685	$	699
2016	72,453		3,235		35,881		1,422		295
2015	69,632		2,043		38,502		1,732		288

Residential mortgage-backed obligations having contractual maturities ranging from 1 to 50 years are included in the following maturity distribution schedules based on their anticipated average life to maturity, which ranges from 2 months to 34 years. Accordingly, discounts are accreted and premiums are amortized over the anticipated average life to maturity of the specific obligation.

The maturities, amortized cost and estimated fair values of securities at December 31, 2017, are summarized as follows:



Dollars in thousands	Amortized Cost		Fair Value
Due in one year or less	$	39,528	$	39,856
Due from one to five years	83,175		83,611
Due from five to ten years	40,809		40,619
Due after ten years	161,259		164,500
Equity securities	137		137
Total	$	324,908	$	328,723

At December 31, 2017 and 2016, securities with estimated fair values of $113.1 million and $103.3 million respectively, were pledged to secure public deposits and for other purposes required or permitted by law.

We held 82 available for sale securities having an unrealized loss at December 31, 2017. We do not intend to sell these securities and it is more likely than not that we will not be required to sell these securities before recovery of their amortized cost bases. We believe that this decline in value is primarily attributable to the lack of market liquidity and to changes in market interest rates and not due to credit quality. Accordingly, no other-than-temporary impairment charge to earnings is warranted at this time.

Provided below is a summary of securities available for sale which were in an unrealized loss position at December 31, 2017 and 2016.



	2017
	Less than 12 months					12 months or more					Total
Dollars in thousands	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss			Fair Value		Unrealized Loss
Temporarily impaired securities
Taxable debt securities
U.S. Government agencies and corporations	$	10,864	$	(91	)	$	2,394	$	(54	)	$	13,258	$	(145	)
Residential mortgage-backed securities:
Government-sponsored agencies	32,156		(269		)	22,584		(634		)	54,740		(903		)
Nongovernment-sponsored entities	5		—			810		(7		)	815		(7		)
State and political subdivisions:
General obligations	6,035		(55		)	—		—			6,035		(55		)
Other revenues	7,532		(62		)	—		—			7,532		(62		)
Corporate debt securities	3,008		(39		)	1,659		(91		)	4,667		(130		)
Tax-exempt debt securities
State and political subdivisions:
General obligations	2,999		(20		)	9,937		(178		)	12,936		(198		)
Water and sewer revenues	282		(3		)	—		—			282		(3		)
Lease revenues	569		(2		)	—		—			569		(2		)
University revenues	1,749		(9		)	—		—			1,749		(9		)
Total temporarily impaired securities	65,199		(550		)	37,384		(964		)	102,583		(1,514		)
Total	$	65,199	$	(550	)	$	37,384	$	(964	)	$	102,583	$	(1,514	)



	2016
	Less than 12 months					12 months or more					Total
Dollars in thousands	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss			Fair Value		Unrealized Loss
Temporarily impaired securities
Taxable debt securities
U.S. Government agencies and corporations	$	763	$	(5	)	$	2,575	$	(43	)	$	3,338	$	(48	)
Residential mortgage-backed securities:
Government-sponsored agencies	55,388		(985		)	8,389		(174		)	63,777		(1,159		)
Nongovernment-sponsored entities	97		—			3,013		(22		)	3,110		(22		)
Corporate debt securities	968		(31		)	3,136		(117		)	4,104		(148		)
Tax-exempt debt securities
State and political subdivisions:
General obligations	33,115		(1,388		)	—		—			33,115		(1,388		)
Water and sewer revenues	4,761		(149		)	—		—			4,761		(149		)
Lease revenues	7,011		(201		)	—		—			7,011		(201		)
Electric revenues	1,973		(48		)	—		—			1,973		(48		)
Sales tax revenues	2,836		(34		)	—		—			2,836		(34		)
Other revenues	8,445		(371		)	—		—			8,445		(371		)
Total temporarily impaired securities	115,357		(3,212		)	17,113		(356		)	132,470		(3,568		)
Total	$	115,357	$	(3,212	)	$	17,113	$	(356	)	$	132,470	$	(3,568	)