MARKETABLE SECURITIES (Tables)

12 Months Ended

Dec. 31, 2016

MARKETABLE SECURITIES

Summary of marketable securities

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(In thousands)
December 31, 2016
Marketable securities
U.S. government and municipal obligations
Maturing in one year or less	$	52,754	$	5	$	(12	)	$	52,747
Maturing after one year through three years		296		8		—			304
Total U.S. government and municipal obligations	$	53,050	$	13	$	(12	)	$	53,051
Corporate debt securities
Maturing in one year or less	$	94,320	$	—	$	(56	)	$	94,264
Maturing after one year through three years		—		—		—			—
Total corporate debt securities	$	94,320	$	—	$	(56	)	$	94,264
Total marketable securities	$	147,370	$	13	$	(68	)	$	147,315
December 31, 2015
Marketable securities
U.S. government and municipal obligations
Maturing in one year or less	$	48,871	$	4	$	(20	)	$	48,855
Maturing after one year through three years		15,940		24		(57	)		15,907
Total U.S. government and municipal obligations	$	64,811	$	28	$	(77	)	$	64,762
Corporate debt securities
Maturing in one year or less	$	129,327	$	2	$	(141	)	$	129,188
Maturing after one year through three years		23,932		1		(102	)		23,831
Total corporate debt securities	$	153,259	$	3	$	(243	)	$	153,019
Total marketable securities	$	218,070	$	31	$	(320	)	$	217,781