Short-Term Investments (Tables)

6 Months Ended

Jun. 30, 2022

Investments, Debt and Equity Securities [Abstract]

Summary of short-term investments

Short-term investments as of December 31, 2021 consisted of the following (in thousands):

			Gross
	Amortized		Unrealized		Estimated
	Cost		Gain (Loss)		Fair Value
Municipal bonds and notes	$	6,001	$	(1)	$	6,000
Zero coupon bonds		123,210		(18)		123,192
Certificates of deposit		530		—		530
Total short-term investments	$	129,741	$	(19)	$	129,722

Short-term investments as of June 30, 2022 consisted of the following (in thousands):

			Gross
	Amortized		Unrealized		Estimated
	Cost		Loss		Fair Value
Municipal bonds and notes	$	999	$	—	$	999
Zero coupon bonds		128,649		(160)		128,489
Certificates of deposit		530		—		530
Total short-term investments	$	130,178	$	(160)	$	130,018