The following table summarizes the amortized cost and fair value of the available for sale investment securities portfolio at September 30, 2021 and December 31, 2020 and the corresponding amounts of unrealized gains and losses recognized in accumulated other comprehensive income:

			Gross		Gross
	Amortized		Unrealized		Unrealized
(In Thousands of Dollars)	Cost		Gains		Losses			Fair Value
September 30, 2021
U.S. Treasury and U.S. government sponsored entities	$	89,919	$	53	$	(1,502	)	$	88,470
State and political subdivisions		485,125		22,776		(618	)		507,283
Corporate bonds		3,604		77		(14	)		3,667
Mortgage-backed securities - residential		569,235		2,778		(5,909	)		566,104
Collateralized mortgage obligations - residential		12,956		290		(5	)		13,241
Small Business Administration		4,471		125		0			4,596
Totals	$	1,165,310	$	26,099	$	(8,048	)	$	1,183,361

			Gross		Gross
	Amortized		Unrealized		Unrealized
(In Thousands of Dollars)	Cost		Gains		Losses			Fair Value
December 31, 2020
U.S. Treasury and U.S. government sponsored entities	$	11,798	$	101	$	(54	)	$	11,845
State and political subdivisions		344,160		22,350		(204	)		366,306
Corporate bonds		3,582		132		(2	)		3,712
Mortgage-backed securities - residential		157,106		4,919		(243	)		161,782
Collateralized mortgage obligations - residential		25,654		742		(3	)		26,393
Small Business Administration		5,411		151		0			5,562
Totals	$	547,711	$	28,395	$	(506	)	$	575,600

Proceeds from the sale of portfolio securities were $8.2 million and $35.2 million during the three and nine month periods ended September 30, 2021, respectively. Gross gains of $458 thousand and $1.4 million along with gross losses of $1 thousand and $515 thousand were realized on these sales during the three and nine month periods ended September 30, 2021. $5 thousand and $141 thousand of realized gains, for equity securities, were recognized in the income statement during the three and nine month periods ended September 30, 2021, respectively.

Proceeds from the sale of portfolio securities were $2.3 million during the three month and $17.7 million during the nine month periods ended September 30, 2020. Gross gains were $48 thousand and $330 thousand for the three and nine month periods ended September 30, 2020, respectively. There were $0 gross losses for the three month period and $12 thousand of realized losses for the nine month period ended September 30, 2020. $22 thousand of realized gains and $117 thousand of realized losses, related to equity securities, were recognized in income during the three and nine month periods ended September 30, 2020, respectively.

The amortized cost and fair value of the debt securities portfolio are shown by expected maturity. Expected maturities may differ from contractual maturities if issuers have the right to call or prepay obligations with or without call or prepayment penalties. Securities not due at a single maturity date are shown separately.

	September 30, 2021
(In Thousands of Dollars)	Amortized Cost		Fair Value
Maturity
Within one year	$	3,791	$	3,820
One to five years		10,360		10,967
Five to ten years		125,179		125,944
Beyond ten years		439,318		458,689
Mortgage-backed, collateralized mortgage obligations and Small Business Administration securities		586,662		583,941
Total	$	1,165,310	$	1,183,361

The following table summarizes the available for sale investment securities with unrealized losses at September 30, 2021 and December 31, 2020, aggregated by major security type and length of time in a continuous unrealized loss position.

	Less than 12 Months					12 Months or Longer					Total
	Fair		Unrealized			Fair		Unrealized			Fair		Unrealized
(In Thousands of Dollars)	Value		Loss			Value		Loss			Value		Loss
September 30, 2021

U.S. Treasury and U.S. government sponsored entities	$	84,849	$	(1,479	)	$	627	$	(23	)	$	85,476	$	(1,502	)
State and political subdivisions		64,442		(562	)		4,579		(56	)		69,021		(618	)
Corporate bonds		533		(11	)		197		(3	)		730		(14	)
Mortgage-backed securities - residential		390,783		(5,909	)		10		0			390,793		(5,909	)
Collateralized mortgage obligations - residential		1,419		(2	)		249		(3	)		1,668		(5	)
Total	$	542,026	$	(7,963	)	$	5,662	$	(85	)	$	547,688	$	(8,048	)

	Less than 12 Months					12 Months or Longer				Total
	Fair		Unrealized			Fair		Unrealized		Fair		Unrealized
(In Thousands of Dollars)	Value		Loss			Value		Loss		Value		Loss
December 31, 2020

U.S. Treasury and U.S. government sponsored entities	$	8,153	$	(54	)	$	0	$	0	$	8,153	$	(54	)
State and political subdivisions		19,205		(204	)		0		0		19,205		(204	)
Corporate bonds		198		(2	)		0		0		198		(2	)
Mortgage-backed securities - residential		63,401		(243	)		0		0		63,401		(243	)
Collateralized mortgage obligations - residential		294		(3	)		0		0		294		(3	)
Total	$	91,251	$	(506	)	$	0	$	0	$	91,251	$	(506	)

The Company has adopted ASU 2016-13 that makes improvements to the accounting for credit losses on securities available for sale. The concept of other than-temporarily impaired securities has been replaced with the allowance for credit losses. Securities available for sale are evaluated on an individual level and pooling of securities is no longer an option. During this evaluation process, management considers the extent to which the fair value has been less than cost, the financial condition and near term prospects of the issuer, and the intent and ability of the Company to hold the security for a period of time sufficient to allow for any anticipated recovery in fair value.

If the Company determines that a credit loss exists, the credit portion of the allowance will be measured using a discounted cash flow analysis using the effective interest rate as of the security’s purchase date. As of September 30, 2021, the Company’s security portfolio consisted of 718 securities, 146 of which were in an unrealized loss position. The majority of the unrealized losses on the Company’s securities are related to its holdings of U.S. Treasury and U.S. government sponsored entities and mortgage-backed securities. The Company does not consider its AFS securities with unrealized losses to be attributable to credit-related factors, as the

unrealized losses have occurred as a result of changes in noncredit related factors such as changes in interest rates, market spreads and market conditions subsequent to purchase, not credit deterioration. As of September 30, 2021 the Company has not recorded an allowance for credit losses on AFS securities.