FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2016

FAIR VALUE MEASUREMENTS

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

        The following table presents the fair value hierarchy for financial assets and liabilities measured at fair value on a recurring basis as of March 31, 2016:

	Level 1		Level 2		Level 3			Total
Cash Equivalents:
Money market funds	$	19,298	$	—	$	—		$	19,298
Short-term investments:
Corporate notes and bonds		—		407,553		—			407,553
U.S. agency obligations		—		97,592		—			97,592
U.S. treasury securities		—		70,340		—			70,340
Commercial paper		—		29,858		—			29,858
Certificates of deposit		—		6,255		—			6,255
Other Current Liabilities:
Contingent consideration		—		—		(2,300	)		(2,300	)
Total	$	19,298	$	611,598	$	(2,300	)	$	628,596

        The following table presents the fair value hierarchy for financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2015:

	Level 1		Level 2		Level 3			Total
Cash Equivalents:
Money market funds	$	2,521	$	—	$	—		$	2,521
Short-term investments:
Corporate notes and bonds		—		387,876		—			387,876
U.S. agency obligations		—		121,329		—			121,329
U.S. treasury securities		—		60,185		—			60,185
Commercial paper		—		36,821		—			36,821
Certificates of deposit		—		7,919		—			7,919
Other Current Liabilities:
Contingent consideration		—		—		(2,300	)		(2,300	)
Total	$	2,521	$	614,130	$	(2,300	)	$	614,351