The following table presents the amortized cost, unrealized gains, unrealized losses and fair value of investment securities available for sale at March 31, 2013 and December 31, 2012. At March 31, 2013 and December 31, 2012, there were no investment securities classified as held to maturity or trading.



(dollars in thousands)	March 31, 2013
	Amortized cost		Unrealized gains		Unrealized losses			Fair value
U.S. government agencies	$	88,079	$	1,333	$	—		$	89,412
Residential pass-through securities	163,455		2,468		(622		)	165,301
Taxable state and political subdivisions	4,756		549		—			5,305
Tax exempt state and political subdivisions	70,848		2,721		(179		)	73,390
Corporate obligations	11,000		44		(129		)	10,915
Agency-issued collateralized mortgage obligations	23,532		39		(75		)	23,496
Asset-backed securities	24,665		44		(181		)	24,528
Investments in mutual funds and other equities	2,018		—		(37		)	1,981
Total investment securities available for sale	$	388,353	$	7,198	$	(1,223	)	$	394,328



(dollars in thousands)	December 31, 2012
	Amortized cost		Unrealized gains		Unrealized losses			Fair value
U.S. government agencies	$	87,297	$	1,321	$	(32	)	$	88,586
Residential pass-through securities	165,175		3,430		(182		)	168,423
Taxable state and political subdivisions	4,759		553		—			5,312
Tax exempt state and political subdivisions	56,431		2,703		(149		)	58,985
Corporate obligations	11,000		—		(565		)	10,435
Agency-issued collateralized mortgage obligations	13,967		79		—			14,046
Asset-backed securities	25,108		150		(70		)	25,188
Investments in mutual funds and other equities	2,018		—		(25		)	1,993
Total investment securities available for sale	$	365,755	$	8,236	$	(1,023	)	$	372,968

Investment securities that were in an unrealized loss position at March 31, 2013 and December 31, 2012, are presented in the following tables, based on the length of time individual securities have been in an unrealized loss position. In the opinion of management, these securities are considered only temporarily impaired due to changes in market interest rates or the widening of market spreads subsequent to the initial purchase of the securities, and not due to concerns regarding the underlying credit of the issuers or the underlying collateral.



(dollars in thousands)	March 31, 2013
	Less than 12 Months					12 Months or Longer					Total
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
Residential pass-through securities	$	53,883	$	(621	)	$	10	$	(1	)	$	53,893	$	(622	)
Tax exempt state and political subdivisions	11,536		(179		)	—		—			11,536		(179		)
Corporate obligations	—		—			2,871		(129		)	2,871		(129		)
Agency-issued collateralized mortgage obligations	9,950		(75		)	—		—			9,950		(75		)
Asset-backed securities	19,497		(181		)	—		—			19,497		(181		)
Investments in mutual funds and other equities	—		—			1,981		(37		)	1,981		(37		)
Total investment securities available for sale	$	94,866	$	(1,056	)	$	4,862	$	(167	)	$	99,728	$	(1,223	)



(dollars in thousands)	December 31, 2012
	Less than 12 Months					12 Months or Longer					Total
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
U.S. government agencies	$	12,056	$	(32	)	$	—	$	—		$	12,056	$	(32	)
Residential pass-through securities	27,680		(182		)	—		—			27,680		(182		)
Tax exempt state and political subdivisions	10,113		(149		)	—		—			10,113		(149		)
Corporate obligations	—		—			10,435		(565		)	10,435		(565		)
Asset-backed securities	9,856		(70		)	—		—			9,856		(70		)
Investments in mutual funds and other equities	—		—			1,993		(25		)	1,993		(25		)
Total investment securities available for sale	$	59,705	$	(433	)	$	12,428	$	(590	)	$	72,133	$	(1,023	)

At March 31, 2013 and December 31, 2012, there were 30 and 25 investment securities in unrealized loss positions, respectively. For each security in an unrealized loss position, the Company assesses whether it intends to sell the security, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. For debt securities that are considered other-than-temporarily impaired and that the Company does not intend to sell and will not be required to sell prior to recovery of its amortized cost basis, the Company will separate the amount of the impairment into the amount that is credit related (credit loss component) and the amount due to all other factors. The credit loss component is recognized in earnings and is calculated as the difference between the security’s amortized cost basis and the present value of its expected future cash flows. The remaining difference between the security’s fair value and the present value of future expected cash flows is deemed to be due to factors that are not credit related and is recognized in other comprehensive income.

The Company does not intend to sell the securities that are temporarily impaired, and it is more likely than not that the Company will not have to sell those securities before recovery of the cost basis. Additionally, the Company has evaluated the credit ratings of its investment securities and their issuers and/or insurers, as applicable. Based on the Company’s evaluation, management has determined that no investment security in the Company’s investment portfolio was other-than-temporarily impaired at March 31, 2013 or December 31, 2012.

The amortized cost and fair value of investment securities, by maturity, are shown in the table below. The amortized cost and fair value of residential pass-through securities, agency-issued collateralized mortgage obligations and asset-backed securities are presented by expected average life, rather than contractual maturity. Expected maturities may differ from contractual maturities because issuers of the securities may have the right to call or prepay obligations with or without call or prepayment penalties.



(dollars in thousands)	March 31, 2013
	Amortized cost		Fair value
Over three months to one year	5,443		5,528
After one year through three years	24,427		25,117
After three years through five years	231,624		234,514
After five years through ten years	95,627		97,315
After ten years	31,232		31,854
Total	$	388,353	$	394,328

The following table presents investment securities which were pledged to secure borrowings and public deposits as permitted or required by law:



(dollars in thousands)	March 31, 2013
	Amortized cost		Fair value
To state and local governments to secure public deposits	$	61,476	$	63,944
To Federal Reserve Bank to secure borrowings	17,502		18,095
To Federal Home Loan Bank to secure borrowings	543		567
Other securities pledged, principally to secure deposits	14,616		15,324
Total pledged investment securities	$	94,137	$	97,930

The following table presents the gross realized gains and gross realized losses on the sale of investment securities available for sale for the three months ended March 31, 2013 and 2012:



(dollars in thousands)	Three Months Ended
	March 31,
	2013		2012
Gross realized gains	265		344
Gross realized losses	—		(2		)
Gain on sale of investment securities, net	$	265	$	342