3.	Securities

The amortized cost, estimated fair value and unrealized gains (losses) of AFS securities are as follows:

(In thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
As of December 31, 2017
Federal agency	$	109,862	$	-	$	963	$	108,899
State & municipal		42,171		62		277		41,956
Mortgage-backed:
Government-sponsored enterprises		530,392		1,406		3,345		528,453
U.S. government agency securities		26,363		334		223		26,474
Collateralized mortgage obligations:
Government-sponsored enterprises		496,033		254		10,114		486,173
U.S. government agency securities		50,721		165		1,065		49,821
Other securities		10,623		3,672		146		14,149
Total AFS securities	$	1,266,165	$	5,893	$	16,133	$	1,255,925
As of December 31, 2016
Federal agency	$	175,135	$	78	$	805	$	174,408
State & municipal		47,053		153		480		46,726
Mortgage-backed:
Government-sponsored enterprises		513,814		3,345		2,492		514,667
U.S. government securities		14,955		411		189		15,177
Collateralized mortgage obligations:
Government-sponsored enterprises		513,431		532		7,688		506,275
U.S. government securities		60,822		184		708		60,298
Other securities		15,849		6,394		1,504		20,739
Total AFS securities	$	1,341,059	$	11,097	$	13,866	$	1,338,290

The components of net realized gains (losses) on the sale of AFS securities are as follows. These amounts were reclassified out of AOCI and into earnings:

	Years ended December 31,
(In thousands)	2017			2016			2015
Gross realized gains	$	2,241		$	683		$	3,099
Gross realized (losses)		(372	)		(1,327	)		(12	)
Net AFS realized gains (losses)	$	1,869		$	(644	)	$	3,087

Included in net gains (losses) from sales transactions, the Company also recorded gains from calls on AFS securities of approximately $0.1 million for each of the years ended December 31, 2017, 2016 and 2015.

In the year ended December 31, 2017, the Company recognized a loss of $2 thousand on HTM securities sales transactions. There were no sales of HTM securities in the year ended December 31, 2016.

At December 31, 2017 and 2016, AFS and HTM securities with amortized costs totaling $1.5 billion were pledged to secure public deposits and for other purposes required or permitted by law. Additionally, at December 31, 2017 and 2016, AFS and HTM securities with an amortized cost of $231.3 million and $235.6 million, respectively, were pledged as collateral for securities sold under the repurchase agreements.

The amortized cost, estimated fair value and unrealized gains (losses) of HTM securities are as follows:

(In thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
As of December 31, 2017
Mortgage-backed:
Government-sponsored enterprises	$	96,357	$	85	$	810	$	95,632
U.S. government agency securities		418		57		-		475
Collateralized mortgage obligations:
Government-sponsored enterprises		186,327		224		2,577		183,974
State & municipal		200,971		1,439		620		201,790
Total HTM securities	$	484,073	$	1,805	$	4,007	$	481,871
As of December 31, 2016
Mortgage-backed:
Government-sponsored enterprises	$	96,668	$	-	$	1,176	$	95,492
U.S. government agency securities		533		87		-		620
Collateralized mortgage obligations:
Government-sponsored enterprises		225,213		1,060		1,508		224,765
State & municipal		205,534		434		1,795		204,173
Total HTM securities	$	527,948	$	1,581	$	4,479	$	525,050

At December 31, 2017 and 2016, all of the mortgaged-backed HTM securities were comprised of U.S. government agency securities.

The following table sets forth information with regard to investment securities with unrealized losses segregated according to the length of time the securities had been in a continuous unrealized loss position:

	Less than 12 months							12 months or longer							Total
(In thousands)	Fair Value		Unrealized Losses			Number of Positions		Fair Value		Unrealized Losses			Number of Positions		Fair Value		Unrealized Losses			Number of Positions

As of December 31, 2017
AFS securities:
Federal agency	$	64,653	$	(242	)		5	$	44,246	$	(721	)		4	$	108,899	$	(963	)		9
State & municipal		23,566		(200	)		39		5,994		(77	)		8		29,560		(277	)		47
Mortgage-backed		317,630		(2,381	)		55		58,316		(1,188	)		24		375,946		(3,569	)		79
Collateralized mortgage obligations		227,917		(2,658	)		35		275,303		(8,521	)		42		503,220		(11,179	)		77
Other securities		-		-			-		2,959		(146	)		1		2,959		(146	)		1
Total securities with unrealized losses	$	633,766	$	(5,481	)		134	$	386,818	$	(10,653	)		79	$	1,020,584	$	(16,134	)		213

HTM securities:
Mortgage-backed	$	15,477	$	(140	)		2	$	33,703	$	(670	)		2	$	49,180	$	(810	)		4
Collateralized mortgage obligations		118,476		(1,064	)		17		37,614		(1,513	)		6		156,090		(2,577	)		23
State & municipal		22,387		(132	)		40		15,720		(488	)		24		38,107		(620	)		64
Total securities with unrealized losses	$	156,340	$	(1,336	)		59	$	87,037	$	(2,671	)		32	$	243,377	$	(4,007	)		91

As of December 31, 2016
AFS securities:
Federal agency	$	119,363	$	(805	)		10	$	-	$	-			-	$	119,363	$	(805	)		10
State & municipal		31,873		(478	)		55		483		(2	)		1		32,356		(480	)		56
Mortgage-backed		277,524		(2,668	)		49		985		(13	)		4		278,509		(2,681	)		53
Collateralized mortgage obligations		473,746		(8,396	)		57		-		-			-		473,746		(8,396	)		57
Other securities		-		-			-		4,363		(1,504	)		2		4,363		(1,504	)		2
Total securities with unrealized losses	$	902,506	$	(12,347	)		171	$	5,831	$	(1,519	)		7	$	908,337	$	(13,866	)		178

HTM securities:
Mortgage-backed	$	95,492	$	(1,176	)		5	$	-	$	-			-	$	95,492	$	(1,176	)		5
Collateralized mortgage obligations		108,587		(319	)		12		35,209		(1,189	)		4		143,796		(1,508	)		16
State & municipal		81,984		(1,795	)		155		-		-			-		81,984		(1,795	)		155
Total securities with unrealized losses	$	286,063	$	(3,290	)		172	$	35,209	$	(1,189	)		4	$	321,272	$	(4,479	)		176

Declines in the fair value of HTM and AFS securities below their amortized cost, less any current period credit loss, that are deemed to be OTTI are reflected in earnings as a realized loss, or in OCI. The classification is dependent upon whether the Company intends to sell the security, or whether it is more likely than not it will be required to sell the security before recovery. The OTTI 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 Company will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the OTTI 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 OTTI related to the credit loss shall be recognized in earnings. The amount of the total OTTI related to other factors shall be recognized in OCI net of applicable taxes.

In estimating OTTI 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 ability and intent to hold the securities classified as HTM until they mature, at which time it is believed the Company will receive full value for the securities. The unrealized losses on HTM debt securities are due to increases in market interest rates over yields 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 if market yields for such investments decline.

Management also has the intent to hold, and will not be required to sell, the securities classified as AFS for a period of time sufficient for a recovery of cost, which may be until maturity. The unrealized losses on AFS debt securities 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. For AFS debt and equity securities, OTTI losses are recognized in earnings if the Company intends to sell the security. In other cases the Company considers the relevant factors noted above, as well as the Company's intent and ability to retain its investment for a period of time sufficient to allow for any anticipated recovery in market value and whether evidence exists to support a realizable value equal to or greater than the cost basis. Any impairment loss on an equity security is equal to the full difference between the cost basis and the fair value of the security.

As of December 31, 2017 and 2016, management believes the impairments detailed in the table above are temporary. For the year ended December 31, 2017, $1.3 million of an OTTI loss on an AFS equity investment was realized in the Company’s consolidated statements of income. There were no OTTI losses realized in the Company’s consolidated statements of income for years ended December 31, 2016 and 2015.

During the year ended December 31, 2017, the Company sold HTM securities with an amortized cost of $0.8 million and an unrealized loss of $2 thousand. Due to significant deterioration in the creditworthiness of the issuers of the HTM securities sold, the Company changed its intent to hold the HTM securities that were sold to maturity, which did not affect the Company's intent to hold the remainder of the HTM portfolio to maturity. There were no sales of HTM securities in the year ended December 31, 2016.

The following tables set forth information with regard to contractual maturities of debt securities at December 31, 2017:

(In thousands)	Amortized Cost		Estimated Fair Value
AFS debt securities:
Within one year	$	63,309	$	63,186
From one to five years		90,119		89,275
From five to ten years		178,128		177,961
After ten years		923,987		911,354
Total AFS debt securities	$	1,255,543	$	1,241,776
HTM debt securities:
Within one year	$	31,412	$	31,413
From one to five years		42,363		42,588
From five to ten years		174,950		174,937
After ten years		235,348		232,933
Total HTM debt securities	$	484,073	$	481,871

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 December 31, 2017 and 2016.