FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Dec. 31, 2014

FAIR VALUE MEASUREMENTS.

Schedule of financial assets subject to fair value measurements

	As of December 31, 2014		Level 1		Level 2		Level 3
	(In thousands)
Money market funds and cash equivalents	$	18,677		—	$	18,677		—
Marketable securities	$	173,023		—	$	173,023		—
	$	191,700		—	$	191,700		—

	As of December 31, 2013		Level 1		Level 2		Level 3
	(In thousands)
Money market funds and cash equivalents	$	148,549		—	$	148,549		—
Marketable securities	$	133,581		—	$	133,581		—
	$	282,130		—	$	282,130		—