MARKETABLE SECURITITES (Tables)

3 Months Ended

Mar. 31, 2020

Marketable Securities [Abstract]

Available-for-sale Securities

Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at March 31, 2020, were as follows:

	Amortized Cost		Gross Unrealized					Estimated Fair Market Value
(In thousands)			Gains		Losses
Investments due in 3 months or less:
Commercial paper	$	14,869	$	—	$	—		$	14,869
Corporate securities	28,104		1		(21		)	28,084
Total	42,973		1		(21		)	42,953
Investments due in 4-12 months:
Corporate securities	63,204		61		(159		)	63,106
Total	63,204		61		(159		)	63,106
Investments due in 12 months or greater:
Corporate securities	126,375		145		(396		)	126,124
Total	126,375		145		(396		)	126,124
Total marketable securities	$	232,552	$	207	$	(576	)	$	232,183

Accrued interest receivable was $1.7 million at March 31, 2020 and was recorded within prepaid expenses and other current assets on the condensed consolidated balance sheet.

Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2019, were as follows:

	Amortized Cost		Gross Unrealized					Estimated Fair Market Value
(In thousands)			Gains		Losses
Investments due in 3 months or less:
Corporate securities	$	15,934	$	18	$	—		$	15,952
Total	15,934		18		—			15,952
Investments due in 4-12 months:
Corporate securities	71,223		269		—			71,492
Total	71,223		269		—			71,492
Investments due in 12 months or greater:
Corporate securities	144,658		302		—			144,954
Total	144,658		302		(6		)	144,954
Total marketable securities	$	231,815	$	589	$	(6	)	$	232,398

Available-for-sale Securities in an Unrealized Loss Position

The following table summarizes marketable securities classified as available-for-sale (excluding cash equivalents) in a continuous unrealized loss position for which an allowance for credit losses has not been recorded at March 31, 2020 and December 31, 2019:

	Less Than 12 Months					12 Months or Longer				Total
(In thousands)	Estimated Fair Market Value		Gross Unrealized Losses			Estimated Fair Market Value		Gross Unrealized Losses		Estimated Fair Market Value		Gross Unrealized Losses
March 31, 2020
Corporate securities	$	138,527	$	(576	)	$	—	$	—	$	138,527	$	(576	)
Total marketable securities	$	138,527	$	(576	)	$	—	$	—	$	138,527	$	(576	)
December 31, 2019
Corporate securities	$	13,069	$	(6	)	$	—	$	—	$	13,069	$	(6	)
Total marketable securities	$	13,069	$	(6	)	$	—	$	—	$	13,069	$	(6	)