Short-term Investments (Tables)

6 Months Ended

Jun. 30, 2021

Investments, Debt and Equity Securities [Abstract]

Short-Term Investments Available-for-Sale Securities

Short-term investments consisted of available-for-sale and equity securities as follows (in thousands):

Type of securities as of June 30, 2021	Amortized cost		Gross unrealized gains		Gross unrealized losses		Fair value
Corporate debt securities	$	182,739	$	7	$	(51)	$	182,695
Government-related debt securities	28,104		—		(18)		28,086
Asset-backed securities	26,857		3		(3)		26,857
Total available-for-sale debt securities	$	237,700	$	10	$	(72)	$	237,638

Type of securities as of December 31, 2020	Amortized cost		Gross unrealized gains		Gross unrealized losses		Fair value
Corporate debt securities	$	22,338	$	71	$	—	$	22,409
Government-related debt securities	5,000		3		—		5,003
Asset-backed securities	1,462		9		—		1,471
Total available-for-sale debt securities	$	28,800	$	83	$	—	$	28,883

Fair Values of Available-for-Sale Securities by Contractual Maturity

The fair values of available-for-sale debt securities by contractual maturity were as follows (in thousands):

	June 30, 2021		December 31, 2020
Maturing in one year or less	$	159,596	$	28,883
Maturing in one to three years	78,042		—
Total available-for-sale debt securities	$	237,638	$	28,883

Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value

The following table summarizes investments that have been in a continuous unrealized loss position as of June 30, 2021 (in thousands).

	Less than 12 months				12 months or greater				Total
	Fair Value		Gross unrealized losses		Fair Value		Gross unrealized losses		Fair Value		Gross unrealized losses
Corporate debt securities	$	45,709	$	(51)	$	—	$	—	$	45,709	$	(51)
Government-related debt securities	23,021		(18)		—		—		23,021		(18)
Asset Backed Securities	11,260		(3)		—		—		11,260		(3)
Total	$	79,990	$	(72)	$	—	$	—	$	79,990	$	(72)