FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 30, 2017

Fair Value Disclosures [Abstract]

Fair value of marketable securities and investments

The fair-value hierarchy of the Company's cash equivalents and marketable securities at June 30, 2017, and December 31, 2016, was as follows:

	Fair Value Measurement at
	June 30, 2017
(In thousands)	Total Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Corporate securities	$	193,901	$	—	$	193,901
Commercial paper	23,654		—		23,654
Government securities	9,366		—		9,366
Money market funds	133		133		—
Total	$	227,054	$	133	$	226,921

	Fair Value Measurement at
	December 31, 2016
(In thousands)	Total Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Corporate securities	$	132,141	$	—	$	132,141
Commercial paper	58,031		—		58,031
Money market funds	1,916		1,916		—
Total	$	192,088	$	1,916	$	190,172