INVESTMENTS

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



	September 30, 2013
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Available for sale securities:
Obligations of U.S. Government-sponsored enterprises	$	93,680	$	599	$	(305	)	$	93,974
Obligations of states and political subdivisions	51,702		1,079		(1,588		)	51,193
Residential mortgage-backed securities	310,907		3,127		(6,155		)	307,879
	$	456,289	$	4,805	$	(8,048	)	$	453,046

	December 31, 2012
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Available for sale securities:
Obligations of U.S. Government-sponsored enterprises	$	149,039	$	3,329	$	—		$	152,368
Obligations of states and political subdivisions	51,202		2,279		(478		)	53,003
Residential mortgage-backed securities	427,221		7,884		(264		)	434,841
	$	627,462	$	13,492	$	(742	)	$	640,212

At September 30, 2013, and December 31, 2012, there were no holdings of securities of any one issuer in an amount greater than 10% of shareholders’ equity, other than the U.S. government agencies and sponsored enterprises. The residential mortgage-backed securities are all issued by U.S. government sponsored enterprises. Available for sale securities having a fair value of $227.5 million and $359.3 million at September 30, 2013, and December 31, 2012, 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 classified as available for sale at September 30, 2013, 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 5 years.



(in thousands)	Amortized Cost		Estimated Fair Value
Due in one year or less	$	885	$	892
Due after one year through five years	107,062		107,703
Due after five years through ten years	23,333		23,516
Due after ten years	14,102		13,056
Mortgage-backed securities	310,907		307,879
	$	456,289	$	453,046

The following table represents a summary of available-for-sale investment securities that had an unrealized loss:



	September 30, 2013
	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 U.S. Government-sponsored enterprises	$	30,355	$	305	$	—	$	—	$	30,355	$	305
Obligations of states and political subdivisions	$	20,306	$	1,230	$	3,042	$	358	$	23,348	$	1,588
Residential mortgage-backed securities	188,849		5,692		8,779		463		197,628		6,155
	$	239,510	$	7,227	$	11,821	$	821	$	251,331	$	8,048

	December 31, 2012
	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	6,434		122		3,389		356		9,823		478
Residential mortgage-backed securities	40,471		143		11,266		121		51,737		264
	$	46,905	$	265	$	14,655	$	477	$	61,560	$	742

The unrealized losses at both September 30, 2013, and December 31, 2012, 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 (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 that the Company would be required to sell the security before its anticipated recovery in market value. At September 30, 2013, 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)	2013		2012		2013			2012
Gross gains realized	$	611	$	—	$	1,477		$	1,399
Gross losses realized	—		—		(182		)	(243		)
Proceeds from sales	36,710		—		159,604			110,876