Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Schedule for Available-for-Sale Securities

The following is a summary of available-for-sale securities as of December 31, 2020 (in thousands):

	Amortized Cost		Gross Unrealized Gain		Gross Unrealized (Losses)		Estimated Fair Value
Corporate debt securities	$	17,086	$	452	$	—	$	17,538
Tax-exempt municipal securities	19,924		365		—		20,289
Total	$	37,010	$	817	$	—	$	37,827

The following is a summary of available-for-sale securities as of December 31, 2019 (in thousands):

	Amortized Cost		Gross Unrealized Gain		Gross Unrealized (Losses)		Estimated Fair Value
Corporate debt securities	$	42,584	$	165	$	(40)	$	42,709
Tax-exempt municipal securities	23,301		112		(215)		23,198
Variable rate demand notes	5,600		—		—		5,600
Total	$	71,485	$	277	$	(255)	$	71,507

Schedule of Maturities of Marketable Securities

The following table summarizes the maturities of the Company’s marketable securities as of December 31, 2019 and 2020 (in thousands):

	December 31, 2019		December 31, 2020
Due within one year	$	34,874	$	7,557
Due after one year through five years	36,633		30,270
Total	$	71,507	$	37,827

Schedule of Proceeds from the Maturities of Available-for-Sale Securities

The following table summarizes the proceeds from the maturities and sales of available-for-sale securities for the years ended December 31, 2018, 2019, and 2020 (in thousands):

	December 31, 2018		December 31, 2019		December 31, 2020
Maturities of marketable securities	$	16,367	$	43,762	$	34,728
Sales of marketable securities	—		—		1,464
Total	$	16,367	$	43,762	$	36,192