FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 30, 2015

FAIR VALUE MEASUREMENTS

Schedule of fair value hierarchy for financial assets measured at fair value on a recurring basis

        The following table presents the fair value hierarchy for financial assets measured at fair value on a recurring basis as of June 30, 2015:

	Level 1		Level 2		Level 3		Total
Cash Equivalents:
Money market funds	$	3,133		—		—	$	3,133
Corporate notes and bonds		—		34,482		—		34,482
U.S. agency obligations		—		30,207		—		30,207
Commercial paper		—		43,888		—		43,888
Short-term investments:
Corporate notes and bonds		—		429,270		—		429,270
U.S. agency obligations		—		68,289		—		68,289
U.S. treasury securities		—		55,436		—		55,436
Commercial paper		—		39,242		—		39,242
Certificates of deposit		—		10,322		—		10,322
Total	$	3,133	$	711,136	$	—	$	714,269