Marketable Securities

3 Months Ended

Mar. 31, 2022

Investments, Debt and Equity Securities [Abstract]

The following is a summary of available-for-sale securities as of March 31, 2022 (in thousands):


	Amortized Cost		Gross Unrealized Gain		Gross Unrealized (Losses)		Estimated Fair Value
Tax-exempt municipal securities	$	18,572	$	31	$	(232)	$	18,371
Corporate debt securities	9,758		5		(72)		9,691
Total	$	28,330	$	36	$	(304)	$	28,062

The following is a summary of available-for-sale securities as of December 31, 2021 (in thousands):


	Amortized Cost		Gross Unrealized Gain		Gross Unrealized (Losses)		Estimated Fair Value
Tax-exempt municipal securities	$	18,546	$	271	$	—	$	18,817
Corporate debt securities	10,898		163		—		11,061
Total	$	29,444	$	434	$	—	$	29,878

The unrealized gains and losses on the Company’s investments in corporate debt and municipal securities as of December 31, 2021 and March 31, 2022 were caused by changes in market values primarily due to interest rate changes. As of March 31, 2022, there were no securities in an unrealized loss position for a period longer than twelve months. The Company has no allowance for credit losses related to its available-for-sale securities as all investments are in investment grade securities. The Company does not intend to sell these securities, and it is not more likely than not that the Company will be required to sell these securities prior to the recovery of their amortized cost basis, which may be at maturity. No impairment charges were recorded during the three months ended March 31, 2021 and 2022.

The following table summarizes the maturities of the Company’s marketable securities as of December 31, 2021 and March 31, 2022 (in thousands):


	December 31, 2021		March 31, 2022
Due within one year	$	6,501	$	6,785
Due after one year through five years	23,377		21,277
Total	$	29,878	$	28,062

The following table summarizes the proceeds from the maturities and sales of available-for-sale securities for the three months ended March 31, 2021 and 2022 (in thousands):


	For the three months ended March 31,
	2021		2022
Maturities of marketable securities	$	1,930	$	1,100
Sales of marketable securities	—		—
Total	$	1,930	$	1,100

The Company did not record any gross realized gains or losses in net income during the three months ended March 31, 2021 and 2022.