Cash and Investments in Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2019

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
	December 31, 2019		December 31, 2018
Cash and cash equivalents	$	96,363	$	194,905
Short-term investments	1,228,499		1,140,445
Long-term investments	279,119		582,889
Total cash and investments in marketable securities	$	1,603,981	$	1,918,239

Portfolio of Cash and Investments in Marketable Securities

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

	Fair Value Hierarchy Level	Estimated Fair Value at
		December 31, 2019		December 31, 2018
Corporate notes and bonds	2	$	1,132,182	$	1,288,986
Corporate commercial paper	2	375,473		498,048
Obligations of U.S. government agencies	2	—		12,977
Available-for-sale investments		1,507,655		1,800,011
Money market funds	1	83,546		105,656
Certificate of deposit	N/A	6,951		6,760
Cash	N/A	5,829		5,812
Total cash and investments in marketable securities		$	1,603,981	$	1,918,239