Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Summary of Available-for-sale Marketable Securities

The following table summarizes the Company’s available-for-sale marketable securities as of December 31, 2021 and 2020 at net book value:

	December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(In thousands)
Marketable securities:
U.S. Treasury and other government securities	$	301,493	$	-	$	(1,016	)	$	300,477
Financial institution debt securities		441,068		-		(652	)		440,416
Corporate debt securities		62,500		-		(151	)		62,349
Other asset-backed securities		159,707		-		(306	)		159,401
Total	$	964,768	$	-	$	(2,125	)	$	962,643
	December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(In thousands)
Marketable securities:
U.S. Treasury and other government securities	$	245,666	$	13	$	(11	)	$	245,668
Financial institution debt securities		138,445		6		(8	)		138,443
Corporate debt securities		41,765		3		(2	)		41,766
Other asset-backed securities		11,474		1		(1	)		11,474
Total	$	437,350	$	23	$	(22	)	$	437,351