
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
	(in thousands)
Available for Sale
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	27,500	$	206	$	277	$	27,429
Obligations of states and political subdivisions		57,221		2,048		67		59,202
Corporate securities		203,519		8,588		365		211,742
Mortgage-backed securities		218,273		4,590		745		222,118

Totals	$	506,513	$	15,432	$	1,454	$	520,491

At September 30, 2021, our holdings of obligations of states and political subdivisions included general obligation bonds with an aggregate fair value of $275.4 million and an amortized cost of $264.2 million. Our holdings at September 30, 2021 also included special revenue bonds with an aggregate fair value of $154.9 million and an amortized cost of $148.5 million. With respect to both categories of those bonds at September 30, 2021, we held no securities of any issuer that comprised more than 10% of our holdings of either bond category. Education bonds and water and sewer utility bonds represented 47% and 35%, respectively, of our total investments in special revenue bonds based on the carrying values of these investments at September 30, 2021. Many of the issuers of the special revenue bonds we held at September 30, 2021 have the authority to impose ad valorem taxes. In that respect, many of the special revenue bonds we held at September 30, 2021 are similar to general obligation bonds.

The amortized cost and estimated fair values of our fixed maturities at December 31, 2020 were as follows:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
	(in thousands)
Held to Maturity
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	77,435	$	3,984	$	223	$	81,196
Obligations of states and political subdivisions		312,319		23,212		143		335,388
Corporate securities		173,270		18,172		206		191,236
Mortgage-backed securities		23,585		1,236		—		24,821

Totals	$	586,609	$	46,604	$	572	$	632,641


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
	(in thousands)
Available for Sale
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	47,512	$	424	$	121	$	47,815
Obligations of states and political subdivisions		66,287		2,690		12		68,965
Corporate securities		202,396		10,496		184		212,708
Mortgage-backed securities		218,763		6,902		17		225,648

Totals	$	534,958	$	20,512	$	334	$	555,136

At December 31, 2020, our holdings of obligations of states and political subdivisions included general obligation bonds with an aggregate fair value of $263.6 million and an amortized cost of $247.5 million. Our holdings also included special revenue bonds with an aggregate fair value of $140.8 million and an amortized cost of $131.1 million. With respect to both categories of bonds, we held no securities of any issuer that comprised more than 10% of that category at December 31, 2020. Education bonds and water and sewer utility bonds represented 44% and 39%, respectively, of our total investments in special revenue bonds based on their carrying values at December 31, 2020. Many of the issuers of the special revenue bonds we held at December 31, 2020 have the authority to impose ad valorem taxes. In that respect, many of the special revenue bonds we held are similar to general obligation bonds.

We made reclassifications from available for sale to held to maturity of certain fixed maturities at fair value on November 30, 2013. We segregated within accumulated other comprehensive income the net unrealized losses of $15.1 million arising prior to the November 30, 2013 reclassifications. We are amortizing this balance over the remaining life of the related securities as an adjustment to yield in a manner consistent with the accretion of discount on the same fixed maturities. We recorded amortization of $

738,815

and $1.1 million in other comprehensive income

(loss)

during the nine months ended September 30, 2021 and 2020, respectively. At September 30, 2021 and December 31, 2020, net unrealized losses of $

5.3

million and $6.1 million, respectively, remained within accumulated other comprehensive income.

We show below the amortized cost and estimated fair value of our fixed maturities at September 30, 2021 by contractual maturity. Expected maturities may differ from contractual maturities because issuers of the securities may have the right to call or pre

ay obligations with or without call or prepayment penalties


	Amortized Cost		Estimated Fair Value
	(in thousands)
Held to maturity
Due in one year or less	$	36,112	$	36,838
Due after one year through five years		82,968		87,988
Due after five years through ten years		232,949		244,151
Due after ten years		291,306		304,474
Mortgage-backed securities		17,745		18,656

Total held to maturity	$	661,080	$	692,107


Available for sale
Due in one year or less	$	22,414	$	22,809
Due after one year through five years		120,648		126,744
Due after five years through ten years		113,678		116,556
Due after ten years		31,500		32,264
Mortgage-backed securities		218,273		222,118

Total available for sale	$	506,513	$	520,491

The cost and estimated fair values of our equity securities at September 30, 2021 were as follows:


	Cost		Gross Gains		Gross Losses		Estimated Fair Value
	(in thousands)
Equity securities	$	50,864	$	20,576	$	257	$	71,183

The cost and estimated fair values of our equity securities at December 31, 2020 were as follows:


	Cost		Gross Gains		Gross Losses		Estimated Fair Value
	(in thousands)
Equity securities	$	42,410	$	17,103	$	957	$	58,556

Gross investment gains and losses before applicable income taxes for the three months and nine months ended September 30, 2021 and 2020 were as follows:


	Three Months Ended September 30,					Nine Months Ended September 30,
	2021			2020		2021		2020
	(in thousands)					(in thousands)
Gross investment gains:
Fixed maturities	$	86		$	159	$	610	$	811
Equity securities		—			3,131		5,287		5,617

		86			3,290		5,897		6,428

Gross investment losses:
Fixed maturities		82			22		156		240
Equity securities		1,574			—		601		7,128

		1,656			22		757		7,368

Net investment (losses) gains	$	(1,570	)	$	3,268	$	5,140	$	(940	)

We recognized $

4.7

million of gains and $

248,146

of losses on equity securities we held at September 30, 2021 in net investment gains for the nine months ended September 30, 2021. We recognized $5.6 million of gains and $3.6 million of losses on equity securities we held at September 30, 2020 in net investment losses for the nine months ended September 30, 2020.

We held fixed maturities with unrealized losses representing declines that we considered temporary at September 30, 2021 as follows:


	Less Than 12 Months				More Than 12 Months
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
	(in thousands)
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	36,355	$	566	$	17,458	$	540
Obligations of states and political subdivisions		77,320		1,327		6,532		189
Corporate securities		56,319		726		3,217		283
Mortgage-backed securities		75,372		742		133		3

Totals	$	245,366	$	3,361	$	27,340	$	1,015

We held fixed maturities with unrealized losses representing declines that we considered temporary at December 31, 2020 as follows:


	Less Than 12 Months				More Than 12 Months
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
	(in thousands)
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	29,144	$	345	$	—	$	—
Obligations of states and political subdivisions		9,362		154		—		—
Corporate securities		26,143		115		8,230		276
Mortgage-backed securities		3,091		15		236		1

Totals	$	67,740	$	629	$	8,466	$	277

We make estimates concerning the valuation of our investments and the recognition of other-than-temporary declines in the value of our investments. For equity securities, we measure investments at fair value, and we recognize changes in fair value in our results of operations. With respect to a debt security that is in an unrealized loss position, we first assess if we intend to sell the debt security. If we determine we intend to sell the debt security, we recognize the impairment loss in our results of operations. If we do not intend to sell the debt security, we determine whether it is more likely than not that we will be required to sell the debt security prior to recovery. If we determine it is more likely than not that we will be required to sell the debt security prior to recovery, we recognize the impairment loss in our results of operations. If we determine it is more likely than not that we will not be required to sell the debt security prior to recovery, we then evaluate whether a credit loss has occurred with respect to that security. We determine whether a credit loss has occurred by comparing the amortized cost of the debt

security to the present value of the cash flows we expect to collect. If we expect a cash flow shortfall, we consider that a credit loss has occurred. If we determine that a credit loss has occurred, we consider the impairment to be other than temporary. We then recognize the amount of the impairment loss related to the credit loss in our results of operations, and we recognize the remaining portion of the impairme

t loss in our other comprehensive income, net of applicable taxes. In addition, we may write down securities in an unrealized loss position based on a number of other factors, including when the fair value of an investment is significantly below its cost, when the financial condition of the issuer of a security has deteriorated, the occurrence of industry, issuer or geographic events that have negatively impacted the value of a security and rating agency downgrades. We held

139

debt securities that were in an unrealized loss position at September 30, 2021. Based upon our analysis of general market cond

tions and underlying factors impacting these debt securities, we considered these declines in value to be temporary.

We amortize premiums and discounts on debt securities over the life of the security as an adjustment to yield using the effective interest method. We compute realized investment gains and losses using the specific identification method.

We amortize premiums and discounts on mortgage-backed debt securities using anticipated prepayments.