FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 30, 2014

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured and Carried at Fair Value

The tables below present information about the Company’s financial assets and liabilities that are measured and carried at fair value and indicate the level within the fair value hierarchy of the valuation techniques it utilizes to determine such fair value:

	Fair Value Measurement as of June 30, 2014
	Total		Level 1		Level 2		Level 3
	(in thousands)
Money market funds	$	277	$	277	$	—	$	—
Commercial paper		20,650		—		20,650
Government and government agency bonds		92,178		—		92,178		—
Corporate bonds		71,207		—		71,207		—
Certificates of deposit		4,647		4,647		—		—
Total assets	$	188,959	$	4,924	$	184,035	$	—

	Fair Value Measurement as of December 31, 2013
	Total		Level 1		Level 2		Level 3
	(in thousands)
Money market funds	$	185,000	$	185,000	$	—	$	—
Certificates of deposit		7,897		7,897		—		—
Total assets	$	192,897	$	192,897	$	—	$	—

	Fair Value Measurement as of June 30, 2014
	Total		Level 1		Level 2		Level 3
	(in thousands)
Warrants	$	9,826	$	—	$	—	$	9,826
Total liabilities	$	9,826	$	—	$	—	$	9,826

	Fair Value Measurement as of December 31, 2013
	Total		Level 1		Level 2		Level 3
	(in thousands)
Warrants	$	9,006	$	—	$	—	$	9,006
Total liabilities	$	9,006	$	—	$	—	$	9,006