Cash and Investments in Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2021

Cash and Cash Equivalents [Abstract]

Schedule of Cash and Investments in Marketable Securities, Including Cash Equivalents

Cash and investments in marketable securities, including cash equivalents, are as follows (in thousands):

	Estimated Fair Value at
	December 31, 2021		December 31, 2020
Cash and cash equivalents	$	25,218	$	198,955
Short-term investments	708,737		862,941
Long-term investments	64,828		136,662
Total cash and investments in marketable securities	$	798,783	$	1,198,558

Schedule of Portfolio of Cash and Investments in Marketable Securities

Our portfolio of cash and investments in marketable securities includes (in thousands):

	Fair Value Hierarchy Level	December 31, 2021								December 31, 2020
		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value		Fair Value
Corporate notes and bonds	2	$	278,475	$	7	$	(361)	$	278,121	$	687,469
Corporate commercial paper	2	478,932		5		(308)		478,629		313,497
Obligations of U.S. government agencies	2	5,880		—		(5)		5,875		2,382
Available-for-sale investments		763,287		12		(674)		762,625		1,003,348
Money market funds	1							23,968		179,302
Certificates of deposit	2							10,940		9,623
Cash	N/A							1,250		6,285
Total cash and investments in marketable securities								$	798,783	$	1,198,558