Investment securities available-for-sale are recorded at fair value on a recurring basis. The Company’s investment securities available-for-sale are measured at fair value using Level 2 valuations. The market evaluation utilizes several sources which include “observable inputs” rather than “significant unobservable inputs” and therefore fall into the Level 2 category. The amortized cost, gross unrealized gains, gross unrealized losses and fair value of investment securities are summarized as follows:

	March 31, 2021
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
State and political subdivisions	$	312,479	$	15,678	$	174	$	327,983
U.S. government agencies		99,349		623		711		99,261
Total	$	411,828	$	16,301	$	885	$	427,244

	December 31, 2020
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
State and political subdivisions	$	287,059	$	18,915	$	─	$	305,974
U.S. government agencies		50,988		764		─		51,752
Total	$	338,047	$	19,679	$	─	$	357,726

	March 31, 2021
	Less than 12 months				12 months or more				Total
(In thousands)	Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses
State and political subdivisions	$	36,423	$	174	$	─	$	─	$	36,423	$	174
U.S. government agencies		60,491		711		─		─		60,491		711
Total	$	96,914	$	885	$	─	$	─	$	96,914	$	885

There were 33 securities, or 12%, (0 greater than 12 months) in an unrealized loss position as of March 31, 2021. There were no securities in an unrealized loss position as of December 31, 2020.

The amortized cost and fair value of investment securities by contractual maturity are shown in the following table. Expected maturities may differ from contractual maturities because borrowers have the right to prepay obligations with or without prepayment penalties.

	March 31, 2021
(In thousands)	Amortized Cost		Fair Value
Due in 1 year or less	$	70,415	$	70,697
Due after 1 year through 5 years		89,351		93,669
Due after 5 years through 10 years		161,771		173,009
Due after 10 years		90,291		89,869
Total	$	411,828	$	427,244

Proceeds from sales of investment securities classified as available for sale were $2,991,000 and $19,629,000 for the three months ended March 31, 2021 and 2020, respectively. Gross realized gains were $48,000 and $1,069,000 for the three months ended March 31, 2021 and 2020, respectively. There were no securities pledged to secure public deposits or for other purposes at March 31, 2021.