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:



	September 30,		December 31,
	2018		2017
	(In thousands)
Cash	$	33,237	$	135,092
Time deposits	4,069		3,682
Money market funds (Level 1)	178,299		116,068
Debt securities issued by the U.S. Treasury (Level 1)	972,682		2,169,197
Total	$	1,188,287	$	2,424,039

Cash and cash equivalents	$	231,571	$	465,851
Restricted cash (included in Other long-term assets)	9,321		9,288
Total Cash, cash equivalents, and restricted cash	240,892		475,139
Marketable securities	947,395		1,948,900
Total	$	1,188,287	$	2,424,039

The fair value of the debt securities held as of September 30, 2018 was $972.7 million, including less than $0.2 million of gross and net unrealized gains. All of the debt securities held as of September 30, 2018 are scheduled to mature in less than one year. The lower Cash and cash equivalents and Marketable securities balances at September 30, 2018 reflect the cash used to settle the principal amount of the Subordinated Convertible Debentures on May 1, 2018, as discussed in Note 8. “Debt and Interest Expense.”

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 September 30, 2018, the carrying value of these financial instruments approximated their fair value. The fair values of the senior notes due 2023 (the “2023 Senior Notes”), the senior notes due 2025 (the “2025 Senior Notes”), and the senior notes due 2027 (the “2027 Senior Notes”) were $762.9 million, $511.5 million, and $536.1 million, respectively, as of September 30, 2018. The fair values of these debt instruments are based on available market information from public data sources and are classified as Level 2. As part of the settlement of the Subordinated Convertible Debentures in the second quarter of 2018, the Company estimated the fair value of the liability component of the debentures, based on the present value of the remaining contractual cash flows, using a discount rate of 8.42% (the estimated borrowing rate for similar non-convertible debt). The fair value of the liability component at the time of extinguishment was $651.3 million and is classified as Level 3.