4. Investment securities:

The amortized cost and fair value of investment securities aggregated by investment category at September 30, 2016 and December 31, 2015 are summarized as follows:


			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
September 30, 2016	Cost		Gains		Losses		Value
Available-for-sale:
U.S. Government-sponsored enterprises	$	67,478	$	218	$	40	$	67,656
State and municipals:
Taxable		14,732		1,023		1		15,754
Tax-exempt		114,699		3,601		3		118,297
Mortgage-backed securities:
U.S. Government agencies		23,300		104		23		23,381
U.S. Government-sponsored enterprises		24,731		156		62		24,825
Total	$	244,940	$	5,102	$	129	$	249,913
Held-to-maturity:
Tax-exempt state and municipals	$	6,863	$	424	$		$	7,287
Mortgage-backed securities:
U.S. Government agencies		72		1				73
U.S. Government-sponsored enterprises		3,929		257				4,186
Total	$	10,864	$	682	$		$	11,546


			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
December 31, 2015	Cost		Gains		Losses		Value
Available-for-sale:
U.S. Treasury securities	$	10,030			$	31	$	9,999
U.S. Government-sponsored enterprises		68,831	$	291		62		69,060
State and municipals:
Taxable		15,842		735		32		16,545
Tax-exempt		121,099		3,915		90		124,924
Mortgage-backed securities:
U.S. Government agencies		31,612		73		117		31,568
U.S. Government-sponsored enterprises		32,928		119		208		32,839
Total	$	280,342	$	5,133	$	540	$	284,935
Held-to-maturity:
Tax-exempt state and municipals	$	6,865	$	186	$	16	$	7,035
Mortgage-backed securities:
U.S. Government agencies		84		1				85
U.S. Government-sponsored enterprises		5,160		326				5,486
Total	$	12,109	$	513	$	16	$	12,606

The maturity distribution of the fair value, which is the net carrying amount, of the debt securities classified as available-for-sale at September 30, 2016, is summarized as follows:


	Fair
September 30, 2016	Value
Within one year	$	34,959
After one but within five years		90,493
After five but within ten years		49,407
After ten years		26,848
		201,707
Mortgage-backed securities		48,206
Total	$	249,913

The maturity distribution of the amortized cost and fair value, of debt securities classified as held-to-maturity at September 30, 2016, is summarized as follows:


	Amortized		Fair
September 30, 2016	Cost		Value
Within one year
After one but within five years
After five but within ten years
After ten years	$	6,863	$	7,287
		6,863		7,287
Mortgage-backed securities		4,001		4,259
Total	$	10,864	$	11,546

Securities with a carrying value of $151,393 and $180,478 at September 30, 2016 and December 31, 2015, respectively, were pledged to secure public deposits and repurchase agreements 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 September 30, 2016 and December 31, 2015, 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 September 30, 2016 and December 31, 2015, 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
September 30, 2016	Value		Losses		Value		Losses		Value		Losses
U.S. Government-sponsored enterprises	$	19,368	$	40					$	19,368	$	40
State and municipals:
Taxable		558		1						558		1
Tax-exempt		3,244		2	$	632	$	1		3,876		3
Mortgage-backed securities:
U.S. Government agencies		7,554		8		1,675		15		9,229		23
U.S. Government-sponsored enterprises		2,359		3		2,478		59		4,837		62
Total	$	33,083	$	54	$	4,785	$	75	$	37,868	$	129


	Less Than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
December 31, 2015	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	9,999	$	31					$	9,999	$	31
U.S. Government-sponsored enterprises		34,159		62						34,159		62
State and municipals:
Taxable					$	532	$	32		532		32
Tax-exempt		21,341		87		1,952		19		23,293		106
Mortgage-backed securities:
U.S. Government agencies		15,114		56		5,477		61		20,591		117
U.S. Government-sponsored enterprises		17,647		104		6,030		104		23,677		208
Total	$	98,260	$	340	$	13,991	$	216	$	112,251	$	556

The Company had 43 investment securities, consisting of one taxable state and municipal obligation, nine U.S. Government-sponsored enterprise securities, 13 tax-exempt state and municipal obligations, and 20 mortgage-backed securities that were in unrealized loss positions at September 30, 2016. Of these securities, one tax-exempt state and municipal obligation and six mortgage-backed 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 September 30, 2016. There was no OTTI recognized for the three or nine months ended September 30, 2016 and 2015.

The Company had 88 investment securities, consisting of 38 tax-exempt state and municipal obligations, one taxable state and municipal obligation, one U.S. Treasury security, 12 U.S. Government-sponsored enterprise securities and 36 mortgage-backed securities that were in unrealized loss positions at December 31, 2015. Of these securities, seven mortgage-backed securities, four tax-exempt state and municipal securities, and one taxable state and municipal obligation were in a continuous unrealized loss position for twelve months or more.