Cash and Investments in Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2020

Fair Value Disclosures [Abstract]

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
	September 30, 2020		December 31, 2019
Cash and cash equivalents	$	55,843	$	96,363
Short-term investments	900,163		1,228,499
Long-term investments	197,715		279,119
Total cash and investments in marketable securities	$	1,153,721	$	1,603,981

Portfolio of Cash and Investments in Marketable Securities

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

		September 30, 2020								December 31, 2019
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value		Fair Value
Corporate notes and bonds	2	$	831,575	$	2,341	$	(201)	$	833,715	$	1,132,182
Corporate commercial paper	2	245,796		131		(14)		245,913		375,473
Obligations of U.S. government agencies	2	9,998		1		—		9,999		—
Available-for-sale investments		$	1,087,369	$	2,473	$	(215)	$	1,089,627	$	1,507,655
Money market funds	1							48,931		83,546
Certificates of deposit	N/A							8,795		6,951
Cash	N/A							6,368		5,829
Total cash and investments in marketable securities								$	1,153,721	$	1,603,981