MARKETABLE SECURITIES

6 Months Ended

Jun. 30, 2018

At June 30, 2018 and December 31, 2017, the fair value of marketable securities are as follows:



	June 30, 2018		December 31, 2017
	(In thousands)
Available-for-sale marketable debt securities	$	119,746	$	4,995
Marketable equity security	664		—
Total marketable securities	$	120,410	$	4,995

At June 30, 2018, current available-for-sale marketable debt securities are as follows:



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(In thousands)
Treasury discount notes	$	99,795	$	6	$	—	$	99,801
Commercial paper	19,945		—		—		19,945
Total available-for-sale marketable debt securities	$	119,740	$	6	$	—	$	119,746

The contractual maturities of debt securities classified as current available-for-sale at June 30, 2018 are within one year. There are no investments in available-for-sale marketable debt securities that are in an unrealized loss position as of June 30, 2018.

At December 31, 2017, current available-for-sale marketable debt securities are as follows:



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(In thousands)
Commercial paper	$	4,995	$	—	$	—	$	4,995
Total available-for-sale marketable debt securities	$	4,995	$	—	$	—	$	4,995

The following table presents the proceeds from maturities and sales of available-for-sale marketable debt securities:



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
	(In thousands)
Proceeds from maturities and sales of available-for-sale marketable debt securities	$	5,000	$	24,000	$	10,000	$	99,350

The specific-identification method is used to determine the cost of available-for-sale marketable debt securities sold and the amount of unrealized gains and losses reclassified out of accumulated other comprehensive income (loss) into earnings. There were no gross realized gains or losses from the maturities and sales of available-for-sale marketable debt securities for the three and six months ended June 30, 2018 and 2017.