Financial Instruments

3 Months Ended

Mar. 31, 2021

Financial Instruments, Owned, at Fair Value [Abstract]

Cash, Cash Equivalents, and Marketable Securities

The following table summarizes the Company’s cash, cash equivalents, and marketable securities and the fair value categorization of the financial instruments measured at fair value on a recurring basis:


	March 31,		December 31,
	2021		2020
	(In thousands)
Cash	$	26,199	$	28,832
Time deposits	3,760		4,176
Money market funds (Level 1)	226,259		129,627
Debt securities issued by the U.S. Treasury (Level 1)	934,365		1,013,679
Total	$	1,190,583	$	1,176,314

Cash and cash equivalents	$	246,811	$	401,194
Restricted cash (included in Other long-term assets)	9,407		9,407
Total Cash, cash equivalents, and restricted cash	256,218		410,601
Marketable securities	934,365		765,713
Total	$	1,190,583	$	1,176,314

The fair value of the debt securities held as of March 31, 2021, included less than $0.1 million of gross and net unrealized gains. All of the debt securities held as of March 31, 2021 are scheduled to mature in less than one year.

Fair Value Measurements

The fair value of the Company’s investments in money market funds approximates their face value. Such instruments are included in Cash and cash equivalents. The fair value of the debt securities consisting of U.S. Treasury bills is based on their quoted market prices. Debt securities purchased with original maturities in excess of three months are included in Marketable securities. The fair value of all of these financial instruments are classified as Level 1 in the fair value hierarchy.

The Company’s other financial instruments include cash, accounts receivable, restricted cash, and accounts payable. As of March 31, 2021, the carrying value of these financial instruments approximated their fair value. The fair values of the senior notes due 2023, 2025, and 2027 were $753.1 million, $563.8 million, and $584.3 million, respectively, as of March 31, 2021. The fair values of these debt instruments are based on available market information from public data sources and are classified as Level 2.