4. Investment securities:

The amortized cost and fair value of investment securities aggregated by investment category at December 31, 2015 and 2014 are summarized as follows:


			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


			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
December 31, 2014	Cost		Gains		Losses		Value
Available-for-sale:
U.S. Treasury securities	$	48,393	$	157			$	48,550
U.S. Government-sponsored enterprises		95,990		337	$	82		96,245
State and municipals:
Taxable		16,490		943		26		17,407
Tax-exempt		87,954		4,971		24		92,901
Mortgage-backed securities:
U.S. Government agencies		37,511		132		167		37,476
U.S. Government-sponsored enterprises		46,956		277		226		47,007
Total	$	333,294	$	6,817	$	525	$	339,586
Held-to-maturity:
Tax-exempt state and municipals	$	7,370	$	105	$	38	$	7,437
Mortgage-backed securities:
U.S. Government agencies		100		2				102
U.S. Government-sponsored enterprises		7,195		481				7,676
Total		14,665	$	588	$	38	$	15,215

The Company had net unrealized gains of $2,985, net of deferred income taxes of $1,608 at December 31, 2015, and $4,090, net of deferred income taxes of $2,202, at December 31, 2014. Proceeds from the sale of investment securities available-for-sale amounted to $81,983 in 2015, $15,389 in 2014, and $4,573 in 2013. Gross gains of $1,189, $919, and $163 were realized on the sale of securities in 2015, 2014, and 2013, respectively. There were no gross losses in 2015 or 2013. Gross losses of $58 were realized on the sale of securities in 2014. The income tax provision applicable to net realized gains amounted to $416, $301, and $55 in 2015, 2014, 2013, respectively.

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, 2015, is summarized as follows:


	Fair
December 31, 2015	Value
Within one year	$	27,675
After one but within five years		96,309
After five but within ten years		49,563
After ten years		46,981
		220,528
Mortgage-backed securities		64,407
Total	$	284,935

The maturity distribution of the amortized cost and fair value, of debt securities classified as held-to-maturity at December 31, 2015, is summarized as follows:


	Amortized		Fair
December 31, 2015	Cost		Value
Within one year	$		$
After one but within five years
After five but within ten years
After ten years		6,865		7,035
		6,865		7,035
Mortgage-backed securities		5,244		5,571
Total	$	12,109	$	12,606

Securities with a carrying value of $180,478 and $216,192 at December 31, 2015 and 2014, 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 December 31, 2015 and 2014, 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, 2015 and 2014, 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, 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


	Less Than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
December 31, 2014	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities
U.S. Government-sponsored enterprises	$	21,228	$	33	$	7,954	$	49	$	29,182	$	82
State and municipals:
Taxable						544		26		544		26
Tax-exempt		4,702		23		2,423		39		7,125		62
Mortgage-backed securities:
U.S. Government agencies		20,148		167						20,148		167
U.S. Government-sponsored enterprises		22,870		226						22,870		226
Total	$	68,948	$	449	$	10,921	$	114	$	79,869	$	563

The Company had 88 investment securities, consisting of 38 tax-exempt state and municipal obligations, one U.S. Treasury security, one taxable state and municipal obligation, twelve 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. 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, 2015.

The Company had 52 investment securities, consisting of 16 tax-exempt state and municipal obligations, one taxable state and municipal obligation, nine U.S. Government-sponsored enterprise securities, and 26 mortgage-backed securities that were in unrealized loss positions at December 31, 2014. Of these securities, two U.S. Government-sponsored enterprise securities, four tax-exempt state and municipal securities and one taxable state and municipal obligation were in continuous unrealized loss positions for twelve months or more. There was no OTTI recognized for each of the years in the three-year period ended December 31, 2015.