Fair value measurements

3 Months Ended

Mar. 31, 2015

The Company’s assets that are measured at fair value on a recurring basis, by level, within the fair value hierarchy are summarized as follows:



	March 31, 2015						December 31, 2014
(in thousands)	Level 1		Level 2		Total		Level 1		Level 2		Total
Cash equivalents:
Money market funds	$	16,618	$	—	$	16,618	$	80,968	$	—	$	80,968
Corporate debt securities	—		—		—		—		2,000		2,000
Total cash equivalents	$	16,618	$	—	$	16,618	$	80,968	$	2,000	$	82,968
Marketable securities:
U.S. treasury securities	$	2,498	$	—	$	2,498	$	1,994	$	—	$	1,994
U.S. agency securities	—		15,287		15,287		—		7,020		7,020
Commercial paper	—		3,697		3,697		—		2,497		2,497
Corporate debt securities	—		147,259		147,259		—		90,816		90,816
Total marketable securities	$	2,498	$	166,243	$	168,741	$	1,994	$	100,333	$	102,327

The Company classifies its cash equivalents and marketable securities as Level 1 or Level 2 within the fair value hierarchy. The fair value of Level 1 financial instruments, which are traded in active markets, is based on quoted market prices for identical instruments. The fair value of Level 2 financial instruments is obtained from an independent pricing service, which may use quoted market prices for identical or comparable instruments or model driven valuations using observable market data or inputs corroborated by observable market data. The Company's procedures include controls to ensure that appropriate fair values are recorded, including comparing the fair values obtained from the Company's pricing service against fair values obtained from other independent sources. At March 31, 2015 and December 31, 2014, the Company had no financial assets or liabilities that were classified as Level 3, which are valued based on inputs supported by little or no market activity.

During the three months ended March 31, 2015, the Company had no transfers of financial assets between levels. At March 31, 2015, $126.5 million of the Company's marketable securities had a contractual maturity of one year or less and $42.2 million had a contractual maturity of one to two years.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References+ Details