Note 12. Securities

The amortized cost, estimated fair value, and unrealized gains and losses of securities available for sale are as follows:

(In thousands)	Amortized cost		Unrealized gains		Unrealized losses		Estimated fair value
March 31, 2013
U.S. Treasury	$	68,557	$	668	$	-	$	69,225
Federal Agency		296,135		1,343		105		297,373
State & municipal		142,714		3,579		41		146,252
Mortgage-backed:
Government-sponsored enterprises		304,955		10,130		25		315,060
U.S. government securities		28,649		1,641		2		30,288
Collateralized mortgage obligations:
Government-sponsored enterprises		526,545		4,247		339		530,453
U.S. government securities		60,093		1,193		1		61,285
Other securities		13,425		2,492		62		15,855
Total securities available for sale	$	1,441,073	$	25,293	$	575	$	1,465,791
December 31, 2012
U.S. Treasury	$	63,668	$	757	$	-	$	64,425
Federal Agency		281,398		1,507		91		282,814
State & municipal		82,675		4,127		-		86,802
Mortgage-backed:
Government-sponsored enterprises		221,110		11,175		-		232,285
U.S. government securities		16,351		1,645		-		17,996
Collateralized mortgage obligations:
Government-sponsored enterprises		399,147		4,418		-		403,565
U.S. government securities		44,825		1,333		-		46,158
Other securities		11,210		2,832		88		13,954
Total securities available for sale	$	1,120,384	$	27,794	$	179	$	1,147,999

Others securities primarily represent marketable equity securities.

Proceeds from the sales of securities available for sale were $2.6 million during the three months ended March 31, 2013, and gains on the sales were $1.1 million. Proceeds from the sales of securities available for sale were $1.8 million during the three months ended March 31, 2012, and gains on the sales were $0.5 million.

Securities with amortized costs totaling $1.5 billion at March 31, 2013 and $1.2 billion at December 31, 2012, were pledged to secure public deposits and for other purposes required or permitted by law. Additionally, at March 31, 2013 and December 31, 2012, securities available for sale with an amortized cost of $236.6 million and $209.0 million, respectively, were pledged as collateral for securities sold under repurchase agreements.

The amortized cost, estimated fair value, and unrealized gains and losses of securities held to maturity are as follows:

	Amortized		Unrealized		Unrealized		Estimated
(In thousands)	cost		gains		losses		fair value
March 31, 2013
Mortgage-backed	$	1,127	$	183	$	-	$	1,310
State & municipal		61,347		704		-		62,051
Total securities held to maturity	$	62,474	$	887	$	-	$	63,361
December 31, 2012
Mortgage-backed	$	1,168	$	184	$	-	$	1,352
State & municipal		59,395		788		-		60,183
Total securities held to maturity	$	60,563	$	972	$	-	$	61,535

The following table sets forth information with regard to investment securities with unrealized losses at March 31, 2013 and December 31, 2012:

	Less than 12 months							12 months or longer							Total
Security Type:	Fair Value		Unrealized losses			Number of Positions		Fair Value		Unrealized losses			Number of Positions		Fair Value		Unrealized losses			Number of Positions

March 31, 2013
U.S. Treasury	$	-	$	-			-	$	-	$	-				$	-	$	-			-
Federal agency		39,955		(105	)		6		-		-			-		39,955		(105	)		6
State & municipal		20,335		(41	)		68		-		-			-		20,335		(41	)		68
Mortgage-backed		15,977		(27	)		11		-		-			-		15,977		(27	)		11
Collateralized mortgage obligations		149,359		(340	)		18		-		-			-		149,359		(340	)		18
Other securities		-		-			-		186		(62	)		1		186		(62	)		1
Total securities with unrealized losses	$	225,626	$	(513	)		103	$	186	$	(62	)		1	$	225,812	$	(575	)		104

December 31, 2012
U.S. Treasury	$	-	$	-			-	$	-	$	-				$	-	$	-			-
Federal agency		39,906		(91	)		4		-		-			-		39,906		(91	)		4
Collateralized mortgage obligations		23		-			2		-		-			-		23		-			2
Other securities		468		(6	)		1		167		(82	)		1		635		(88	)		2
Total securities with unrealized losses	$	40,397	$	(97	)		7	$	167	$	(82	)		1	$	40,564	$	(179	)		8

Declines in the fair value of held-to-maturity and available-for-sale securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses or in other comprehensive income, depending on whether the Company intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss. If the Company intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the other-than-temporary impairment shall be recognized in earnings equal to the entire difference between the investment's amortized cost basis and its fair value at the balance sheet date. If the Company does not intend to sell the security and it is not more likely than not that the entity will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the other-than-temporary impairment shall be separated into (a) the amount representing the credit loss and (b) the amount related to all other factors. The amount of the total other-than-temporary impairment related to the credit loss shall be recognized in earnings. The amount of the total other-than-temporary impairment related to other factors shall be recognized in other comprehensive income, net of applicable taxes.

In estimating other-than-temporary impairment losses, management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, and (iii) the historical and implied volatility of the fair value of the security.

Management has the intent to hold the securities classified as held to maturity until they mature, at which time it is believed the Company will receive full value for the securities. Furthermore, as of March 31, 2013, management also had the intent to hold, and will not be required to sell, the securities classified as available for sale for a period of time sufficient for a recovery of cost, which may be until maturity. The unrealized losses are due to increases in market interest rates over the yields available at the time the underlying securities were purchased. When necessary, the Company has performed a discounted cash flow analysis to determine whether or not it will receive the contractual principal and interest on certain securities. The fair value is expected to recover as the bonds approach their maturity date or repricing date or if market yields for such investments decline. As of March 31, 2013, management believes the impairments detailed in the table above are temporary and no other-than-temporary impairment losses have been realized in the Company's consolidated statements of income.

The following tables set forth information with regard to contractual maturities of debt securities at March 31, 2013:

(In thousands)	Amortized cost		Estimated fair value
Debt securities classified as available for sale
Within one year	$	45,889	$	46,070
From one to five years		184,744		187,836
From five to ten years		382,001		388,831
After ten years		815,014		827,199
	$	1,427,648	$	1,449,936
Debt securities classified as held to maturity
Within one year	$	24,547	$	24,598
From one to five years		28,732		29,380
From five to ten years		6,125		6,130
After ten years		3,070		3,253
	$	62,474	$	63,361

Maturities of mortgage-backed, collateralized mortgage obligations and asset-backed securities are stated based on their estimated average lives. Actual maturities may differ from estimated average lives or contractual maturities because, in certain cases, borrowers have the right to call or prepay obligations with or without call or prepayment penalties.

Except for U.S. Government securities, there were no holdings, when taken in the aggregate, of any single issuer that exceeded 10% of consolidated stockholders' equity at March 31, 2013.