Investments, Available-for-Sale (Tables)

12 Months Ended

Dec. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Schedule of Investments, Available-for-Sale

Investments, available-for-sale, consisted of the following, in thousands:

December 31, 2021	Maturity in years	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
US government and government agency notes	Less than 1	$	89,011	$	—	$	(37)	$	88,974
Corporate debt securities	Less than 1	122,408		—		(186)		122,222
Commercial paper	Less than 1	114,733		—		(32)		114,701
Short-term investments, available-for-sale		$	326,152	$	—	$	(255)	$	325,897
US government and government agency notes	1 - 5	$	106,501	$	—	$	(291)	$	106,210
Corporate debt securities	1 - 5	54,751		—		(165)		54,586
Investments, available-for-sale		$	161,252	$	—	$	(456)	$	160,796
December 31, 2020	Maturity in years	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
US government and government agency notes	Less than 1	$	621,281	$	178	$	(59)	$	621,400
Corporate debt securities	Less than 1	160,244		362		(38)		160,568
Commercial paper	Less than 1	102,513		22		(6)		102,529
Short-term investments, available-for-sale		$	884,038	$	562	$	(103)	$	884,497