3. Investment securities:

The amortized cost and fair value of investment securities aggregated by investment category at December 31, 2017 and 2016 are summarized as follows:


			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
December 31, 2017	Cost		Gains		Losses		Value
Available-for-sale:
U.S. Treasury securities	$	20,042	$		$	228	$	19,814
U.S. Government-sponsored enterprises		95,358		30		1,740		93,648
State and municipals:
Taxable		14,559		488				15,047
Tax-exempt		103,199		1,136		502		103,833
Residential Mortgage-backed securities:
U.S. Government agencies		14,517		2		85		14,434
U.S. Government-sponsored enterprises		19,752		10		231		19,531
Commercial Mortgage-backed securities:
U.S. Government-sponsored enterprises		6,315				120		6,195
Common equity securities		43		3				46
Total	$	273,785	$	1,669	$	2,906	$	272,548
Held-to-maturity:
Tax-exempt state and municipals	$	6,859	$	152	$	13	$	6,998
Residential Mortgage-backed securities:
U.S. Government agencies		54						54
U.S. Government-sponsored enterprises		2,361		138		4		2,495
Total	$	9,274	$	290	$	17	$	9,547


			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
December 31, 2016	Cost		Gains		Losses		Value
Available-for-sale:
U.S. Treasury securities	$	7,570			$	132	$	7,438
U.S. Government-sponsored enterprises		82,314	$	79		1,480		80,913
State and municipals:
Taxable		14,698		566		39		15,225
Tax-exempt		110,931		2,309		640		112,600
Residential Mortgage-backed securities:
U.S. Government agencies		21,041		48		47		21,042
U.S. Government-sponsored enterprises		22,303		48		159		22,192
Total	$	258,857	$	3,050	$	2,497	$	259,410
Held-to-maturity:
Tax-exempt state and municipals	$	6,862	$	72	$	67	$	6,867
Residential Mortgage-backed securities:
U.S. Government agencies		68		1				69
U.S. Government-sponsored enterprises		3,587		191				3,778
Total	$	10,517	$	264	$	67	$	10,714

The Company had net unrealized losses on available-for-sale securities of $977, net of deferred income taxes of $260 at December 31, 2017, and net unrealized gains of $360, net of deferred income taxes of $193, at December 31, 2016. There were no investment securities sales in 2017, proceeds from the sale of investment securities available-for-sale amounted to $27,408 in 2016 and $81,983 in 2015. There were no realized gains or losses on investment securities in 2017. Gross realized gains totaled $623 in 2016 and $1,189 in 2015. There were no gross losses in 2016 or 2015.

The maturity distribution of the fair value, which is the net carrying amount, of the debt securities classified as available-for-sale at December 31, 2017, is summarized as follows:


	Fair
December 31, 2017	Value
Within one year	$	12,238
After one but within five years		168,657
After five but within ten years		35,278
After ten years		16,169
		232,342
Mortgage-backed securities		40,160
Total	$	272,502

Expected maturities will differ from contractual maturities because borrowers have the right to call or prepay obligations with or without call or prepayment penalties.

The maturity distribution of the amortized cost and fair value, of debt securities classified as held-to-maturity at December 31, 2017, is summarized as follows:


	Amortized		Fair
December 31, 2017	Cost		Value
Within one year
After one but within five years
After five but within ten years
After ten years	$	6,859	$	6,998
		6,859		6,998
Mortgage-backed securities		2,415		2,549
Total	$	9,274	$	9,547

Securities with a carrying value of $163,936 and $144,750 at December 31, 2017 and 2016, respectively, were pledged to secure public deposits and certain other deposits as required or permitted by law.

Securities and short-term investment activities are conducted with a diverse group of government entities, corporations and state and local municipalities. The counterparty’s creditworthiness and type of collateral is evaluated on a case-by-case basis. At December 31, 2017 and 2016, there were no significant concentrations of credit risk from any one issuer, with the exception of U.S. Government agencies and sponsored enterprises that exceeded 10.0 percent of stockholders’ equity.

The fair value and gross unrealized losses of investment securities with unrealized losses for which an OTTI has not been recognized at December 31, 2017 and 2016, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position, are summarized as follows:


	Less Than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
December 31, 2017	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	17,350	$	170	$	2,464	$	58	$	19,814	$	228
U.S. Government-sponsored enterprises		39,096		445		51,365		1,295		90,461		1,740
State and municipals:
Taxable
Tax-exempt		54,788		454		3,808		61		58,596		515
Residential Mortgage-backed securities:
U.S. Government agencies		9,484		39		3,968		46		13,452		85
U.S. Government-sponsored enterprises		12,537		103		6,504		132		19,041		235
Commercial Mortgage-backed securities:
U.S. Government-sponsored enterprises		6,195		120						6,195		120
Total	$	139,450	$	1,331	$	68,109	$	1,592	$	207,559	$	2,923


	Less Than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
December 31, 2016	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	7,438	$	132					$	7,438	$	132
U.S. Government-sponsored enterprises		59,460		1,480						59,460		1,480
State and municipals:
Taxable		1,035		39						1,035		39
Tax-exempt		55,166		707	$	226				55,392		707
Residential Mortgage-backed securities:
U.S. Government agencies		5,917		27		1,496	$	20		7,413		47
U.S. Government-sponsored enterprises		16,412		85		2,712		74		19,124		159
Total	$	145,428	$	2,470	$	4,434	$	94	$	149,862	$	2,564

The Company had 186 investment securities, consisting of 103 tax-exempt state and municipal obligations, seven U.S. Treasury securities, one taxable state and municipal obligation, 35 U.S. Government-sponsored enterprise securities and 40 mortgage-backed securities that were in unrealized loss positions at December 31, 2017. Of these securities, one U.S. Treasury security, twenty U.S. Government–sponsored enterprise securities, seventeen mortgage-backed securities and seven tax-exempt state and municipal securities were in a continuous unrealized loss position for twelve months or more. Management does not consider the unrealized losses on the debt securities, as a result of changes in interest rates, to be OTTI based on historical evidence that indicates the cost of these securities is recoverable within a reasonable period of time in relation to normal cyclical changes in the market rates of interest. Moreover, because there has been no material change in the credit quality of the issuers or other events or circumstances that may cause a significant adverse impact on the fair value of these securities, and management does not intend to sell these securities and it is unlikely that the Company will be required to sell these securities before recovery of their amortized cost basis, which may be maturity, the Company does not consider the unrealized losses to be OTTI at December 31, 2017.

There was no OTTI recognized for each of the years in the three-year period ended December 31, 2017.