4. Investment securities:

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


			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
March 31, 2017	Cost		Gains		Losses		Value
Available-for-sale:
U.S. Treasury securities	$	20,050	$	1	$	156	$	19,895
U.S. Government-sponsored enterprises		83,677		72		1,277		82,472
State and municipals:
Taxable		14,663		604				15,267
Tax-exempt		105,894		2,104		461		107,537
Mortgage-backed securities:
U.S. Government agencies		19,321		47		36		19,332
U.S. Government-sponsored enterprises		20,213		46		118		20,141
Total	$	263,818	$	2,874	$	2,048	$	264,644
Held-to-maturity:
Tax-exempt state and municipals	$	6,861	$	86	$	83	$	6,864
Mortgage-backed securities:
U.S. Government agencies		64						64
U.S. Government-sponsored enterprises		3,255		176				3,431
Total	$	10,180	$	262	$	83	$	10,359


			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 March 31, 2017, is summarized as follows:


	Fair
March 31, 2017	Value
Within one year	$	39,613
After one but within five years		118,950
After five but within ten years		49,157
After ten years		17,451
		225,171
Mortgage-backed securities		39,473
Total	$	264,644

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


	Amortized		Fair
March 31, 2017	Cost		Value
Within one year
After one but within five years
After five but within ten years
After ten years	$	6,861	$	6,864
		6,861		6,864
Mortgage-backed securities		3,319		3,495
Total	$	10,180	$	10,359

Securities with a carrying value of $142,335 and $144,750 at March 31, 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 March 31, 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 March 31, 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
March 31, 2017	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	17,411	$	156					$	17,411	$	156
U.S. Government-sponsored enterprises		62,591		1,277						62,591		1,277
State and municipals:
Taxable
Tax-exempt		51,467		544						51,467		544
Mortgage-backed securities:
U.S. Government agencies		5,769		23	$	1,337	$	13		7,106		36
U.S. Government-sponsored enterprises		13,832		66		2,380		52		16,212		118
Total	$	151,070	$	2,066	$	3,717	$	65	$	154,787	$	2,131


	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 150 investment securities, consisting of 93 tax-exempt state and municipal obligations, six U.S. Treasury securities, 23 U.S. Government-sponsored enterprise securities, and 28 mortgage-backed securities that were in unrealized loss positions at March 31, 2017. Of these securities, eight 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 March 31, 2017. There was no OTTI recognized for the three months ended March 31, 2017 and 2016.

The Company had 163 investment securities, consisting of 107 tax-exempt state and municipal obligations, two taxable state and municipal obligation, 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.