Fair Value Measurements

12 Months Ended

Dec. 31, 2014

Fair Value Disclosures [Abstract]

Fair Value Measurements

4. Fair Value Measurements

The Company establishes the fair value of its assets and liabilities using the price that would be received to sell an asset or paid to transfer a financial liability in an orderly transaction between market participants at the measurement date. A fair value hierarchy is used to measure fair value. The three levels of the fair value hierarchy are as follows:

Level 1: Quoted prices in active markets for identical assets and liabilities.

Level 2: Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets.

Level 3: Valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable.

The Company’s available-for-sale securities by level within the fair value hierarchy were as follows:

As of December 31, 2014	Fair value measurement using:
	Level 1		Level 2		Level 3		Total
	(In thousands)
Cash equivalents:
Money market fund	$	13,426	$	—	$	—	$	13,426
Short-term investments:
U.S. government-related debt securities		—		4,498		—		4,498
Corporate debt securities		—		47,307		—		47,307
Asset-backed securities		—		3,197		—		3,197
Total	$	13,426	$	55,002	$	—	$	68,428
As of December 31, 2013	Fair value measurement using:
	Level 1		Level 2		Level 3		Total
	(In thousands)
Cash equivalents:
Money market fund	$	8,454	$	—	$	—	$	8,454
Short-term investments:
U.S. government-related debt securities		—		1,566		—		1,566
Corporate debt securities		—		31,149		—		31,149
Total	$	8,454	$	32,715	$	—	$	41,169