4. Investment securities:

The amortized cost and fair value of investment securities aggregated by investment category at June 30, 2017 and December 31, 2016 are summarized as follows:


			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
June 30, 2017	Cost		Gains		Losses		Value
Available-for-sale:
U.S. Treasury securities	$	20,047	$	56	$	23	$	20,080
U.S. Government-sponsored enterprises		81,495		96		847		80,744
State and municipals:
Taxable		14,629		667		1		15,295
Tax-exempt		102,737		2,191		59		104,869
Mortgage-backed securities:
U.S. Government agencies		17,576		31		29		17,578
U.S. Government-sponsored enterprises		18,280		39		111		18,208
Total	$	254,764	$	3,080	$	1,070	$	256,774
Held-to-maturity:
Tax-exempt state and municipals	$	6,860	$	163	$	3	$	7,020
Mortgage-backed securities:
U.S. Government agencies		61						61
U.S. Government-sponsored enterprises		2,947		193				3,140
Total	$	9,868	$	356	$	3	$	10,221


			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
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
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 maturity distribution of the fair value, which is the net carrying amount, of the debt securities classified as available-for-sale at June 30, 2017, is summarized as follows:


	Fair
June 30, 2017	Value
Within one year	$	33,157
After one but within five years		127,433
After five but within ten years		45,799
After ten years		14,599
		220,988
Mortgage-backed securities		35,786
Total	$	256,774

The maturity distribution of the amortized cost and fair value, of debt securities classified as held-to-maturity at June 30, 2017, is summarized as follows:


	Amortized		Fair
June 30, 2017	Cost		Value
Within one year
After one but within five years
After five but within ten years
After ten years	$	6,860	$	7,020
		6,860		7,020
Mortgage-backed securities		3,008		3,201
Total	$	9,868	$	10,221

Securities with a carrying value of $138,272 and $144,750 at June 30, 2017 and December 31, 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 June 30, 2017 and December 31, 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 other-than-temporary impairment (“OTTI”) has not been recognized at June 30, 2017 and December 31, 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
June 30, 2017	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	2,501	$	23					$	2,501	$	23
U.S. Government-sponsored enterprises		65,845		823	$	1,067	$	24		66,912		847
State and municipals:
Taxable		554		1						554		1
Tax-exempt		15,898		62						15,898		62
Mortgage-backed securities:
U.S. Government agencies		2,848		8		3,503		21		6,351		29
U.S. Government-sponsored enterprises		11,218		50		2,327		61		13,545		111
Total	$	98,864	$	967	$	6,897	$	106	$	105,761	$	1,073


	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
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 80 investment securities, consisting of 27 tax-exempt state and municipal obligations, one U.S. Treasury security, one taxable municipal obligation, 25 U.S. Government-sponsored enterprise securities, and 26 mortgage-backed securities that were in unrealized loss positions at June 30, 2017. Of these securities, eleven mortgage-backed securities and one U.S. Government-sponsored enterprise security 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 June 30, 2017. There was no OTTI recognized for the three or six months ended June 30, 2017 and 2016.

The Company had 163 investment securities, consisting of 107 tax-exempt state and municipal obligations, two taxable state and municipal obligations, two U.S. Treasury securities, 22 U.S. Government-sponsored enterprise securities and 30 mortgage-backed securities that were in unrealized loss positions at December 31, 2016. Of these securities, nine mortgage-backed securities, and two tax-exempt state and municipal securities were in a continuous unrealized loss position for twelve months or more.