INVESTMENTS

The following table presents the amortized cost, gross unrealized gains and losses and fair value of securities available for sale and held to maturity:



	September 30, 2016
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Available for sale securities:
Obligations of U.S. Government-sponsored enterprises	$	97,745	$	1,313	$	—		$	99,058
Obligations of states and political subdivisions	37,132		1,511		(307		)	38,336
Agency mortgage-backed securities	336,693		5,826		(304		)	342,215
Total securities available for sale	$	471,570	$	8,650	$	(611	)	$	479,609
Held to maturity securities:
Obligations of states and political subdivisions	$	14,777	$	359	$	(2	)	$	15,134
Agency mortgage-backed securities	26,254		830		—			27,084
Total securities held to maturity	$	41,031	$	1,189	$	(2	)	$	42,218



	December 31, 2015
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Available for sale securities:
Obligations of U.S. Government-sponsored enterprises	$	98,699	$	309	$	—		$	99,008
Obligations of states and political subdivisions	40,700		1,343		(342		)	41,701
Agency mortgage-backed securities	311,516		2,046		(2,501		)	311,061
Total securities available for sale	$	450,915	$	3,698	$	(2,843	)	$	451,770
Held to maturity securities:
Obligations of states and political subdivisions	$	14,831	$	63	$	(50	)	$	14,844
Agency mortgage-backed securities	28,883		—		(286		)	28,597
Total securities held to maturity	$	43,714	$	63	$	(336	)	$	43,441

At September 30, 2016, and December 31, 2015, there were no holdings of securities of any one issuer in an amount greater than 10% of shareholders’ equity, other than U.S. Government agencies and sponsored enterprises. The agency mortgage-backed securities are all issued by U.S. Government-sponsored enterprises. Available for sale securities having a fair value of $321.5 million and $334.4 million at September 30, 2016, and December 31, 2015, respectively, were pledged as collateral to secure deposits of public institutions and for other purposes as required by law or contract provisions.

The amortized cost and estimated fair value of debt securities at September 30, 2016, by contractual maturity, are shown below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. The weighted average life of the mortgage-backed securities is approximately 4 years.



	Available for sale				Held to maturity
(in thousands)	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due in one year or less	$	52,384	$	52,637	$	—	$	—
Due after one year through five years	70,128		72,153		8,189		8,356
Due after five years through ten years	8,836		9,328		6,588		6,778
Due after ten years	3,529		3,276		—		—
Agency mortgage-backed securities	336,693		342,215		26,254		27,084
	$	471,570	$	479,609	$	41,031	$	42,218

The following table represents a summary of investment securities that had an unrealized loss:



	September 30, 2016
	Less than 12 months				12 months or more				Total
(in thousands)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Obligations of states and political subdivisions	$	—	$	—	$	3,566	$	309	$	3,566	$	309
Agency mortgage-backed securities	6,654		11		13,379		293		20,033		304
	$	6,654	$	11	$	16,945	$	602	$	23,599	$	613

	December 31, 2015
	Less than 12 months				12 months or more				Total
(in thousands)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Obligations of states and political subdivisions	$	2,199	$	12	$	9,395	$	380	$	11,594	$	392
Agency mortgage-backed securities	189,229		2,050		21,020		737		210,249		2,787
	$	191,428	$	2,062	$	30,415	$	1,117	$	221,843	$	3,179

The unrealized losses at both September 30, 2016, and December 31, 2015, were primarily attributable to changes in market interest rates since the securities were purchased. Management systematically evaluates investment securities for other-than-temporary declines in fair value on a quarterly basis. This analysis requires management to consider various factors, which include among other considerations (1) the present value of the cash flows expected to be collected compared to the amortized cost of the security, (2) duration and magnitude of the decline in value, (3) the financial condition of the issuer or issuers, (4) structure of the security, and (5) the intent to sell the security or whether it is more likely than not the Company would be required to sell the security before its anticipated recovery in market value. At September 30, 2016, management performed its quarterly analysis of all securities with an unrealized loss and concluded no individual securities were other-than-temporarily impaired.

The gross gains and gross losses realized from sales of available for sale investment securities were as follows:



	Three months ended September 30,				Nine months ended September 30,
(in thousands)	2016		2015		2016		2015
Gross gains realized	$	86	$	—	$	86	$	63
Gross losses realized	—		—		—		(40		)
Proceeds from sales	2,493		—		2,493		41,069