Fair Value Measurements

6 Months Ended

Jun. 30, 2016

Fair Value Disclosures [Abstract]

Fair Value Measurements

4. Fair Value Measurements

The Company determines the fair value of financial assets and liabilities using three levels of inputs as follows:

Level 1—Inputs which include quoted prices in active markets for identical assets and liabilities.

Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

The Company’s financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements are as follows as of June 30, 2016 and December 31, 2015 (in thousands):

	June 30, 2016
Description	Level 1		Level 2		Level 3		Total
Money market fund	$	21,715	$	—	$	—		21,715
U.S. treasury securities		—		21,192		—		21,192
Government-sponsored agencies		—		16,969		—		16,969
Commercial paper		—		20,323		—		20,323
Corporate debt securities		—		59,445		—		59,445
Total assets	$	21,715	$	117,929	$	—	$	139,644
	December 31, 2015
Description	Level 1		Level 2		Level 3		Total
Money market fund	$	11,340	$	—	$	—	$	11,340
U.S. treasury securities		—		14,026		—		14,026
Government-sponsored agencies		—		30,934		—		30,934
Commercial paper		—		3,992		—		3,992
Corporate debt securities		—		14,514		—		14,514
Total assets	$	11,340	$	63,466	$	—	$	74,806

During the six months ended June 30, 2016, there were no transfers between Level 1 and Level 2 financial assets. When the Company uses observable market prices for identical securities that are traded in less active markets, the Company classifies its marketable debt instruments as Level 2. When observable market prices for identical securities are not available, the Company prices its marketable debt instruments using non-binding market consensus prices that are corroborated with observable market data; quoted market prices for similar instruments; or pricing models, such as a discounted cash flow model, with all significant inputs derived from or corroborated with observable market data. Non-binding market consensus prices are based on the proprietary valuation models of pricing providers or brokers. These valuation models incorporate a number of inputs, including non-binding and binding broker quotes; observable market prices for identical or similar securities; and the internal assumptions of pricing providers or brokers that use observable market inputs and, to a lesser degree, unobservable market inputs. The Company corroborates non-binding market consensus prices with observable market data using statistical models when observable market data exists. The discounted cash flow model uses observable market inputs, such as LIBOR-based yield curves, currency spot and forward rates, and credit ratings.