Financial Instruments

6 Months Ended

Jun. 30, 2022

Investments, Debt and Equity Securities [Abstract]

Investments in Marketable Debt Securities

As of June 30, 2022, the weighted-average remaining contractual life, amortized cost, gross unrealized gains, gross unrealized losses and fair value of marketable debt securities, which were considered as available-for-sale, by type of security were as follows (in thousands):


	June 30, 2022
	(Unaudited)
	Weighted- Average Remaining Contractual Life (in years)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value

Current:
Corporate debt securities	0.1	$	14,764	$	—	$	(9)	$	14,755

Mutual funds		34		9		(6)		37
Current portion		14,798		9		(15)		14,792
Noncurrent:
Foreign bonds	4.8	969		1		(56)		914
Noncurrent portion		969		1		(56)		914
Total		$	15,767	$	10	$	(71)	$	15,706

As of December 31, 2021, the amortized cost, gross unrealized gains, gross unrealized losses and fair value of marketable debt securities, which were considered as available-for-sale, by type of security were as follows (in thousands):


	December 31, 2021
	Weighted- Average Remaining Contractual Life (in years)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value

Current:
Corporate debt securities	0.5	$	129,190	$	10	$	(36)	$	129,164
Foreign bonds	0.4	116		—		(1)		115
Mutual funds		35		3		—		38
Current portion		129,341		13		(37)		129,317
Noncurrent:
Foreign bonds	5.0	719		103		—		822
Noncurrent portion		719		103		—		822
Total		$	130,060	$	116	$	(37)	$	130,139

Accumulated unrealized losses on marketable debt securities that have been in a continuous loss position for less than 12 months and more than 12 months were as follows (in thousands):


	June 30, 2022
	(Unaudited)
	Less than 12 months				More than 12 months
	Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses

Corporate debt securities	$	7,074	$	(9)	$	—	$	—
Mutual funds	—		—		31		(6)
Foreign bonds	720		(41)		89		(15)
Total	$	7,794	$	(50)	$	120	$	(21)


	December 31, 2021
	Less than 12 months				More than 12 months
	Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses

Corporate debt securities	$	86,158	$	(36)	$	—	$	—
Mutual funds	—		—		34		(2)
Foreign bonds	115		(1)		113		(1)
Total	$	86,273	$	(37)	$	147	$	(3)

Realized gains and losses on sales of available-for-sale marketable debt securities were not material for the three and six months ended June 30, 2022 and 2021.

Marketable Equity Securities

We held investments in marketable equity securities with readily determinable fair values of $6.2 million and $6.7 million as of June 30, 2022 and December 31, 2021, respectively. Unrealized losses recorded on these securities totaled $1.9 million and $0.4 million for the three months ended June 30, 2022 and 2021, respectively, and unrealized losses and gains totaled a $0.5 million loss and an $8.4 million gain for the six months ended June 30, 2022 and 2021, respectively, in interest and investment income loss (income), net, on the condensed consolidated statements of operations.