The Company applies the provisions of ASC 820, “Fair Value Measurements and Disclosures,” for financial assets and liabilities measured on a recurring basis which requires disclosure that establishes a framework for measuring fair value and expands disclosures in the financial statements. The guidance requires that fair value measurements be classified and disclosed in one of the three categories:

Level 1: Quoted prices in active markets for identical assets and liabilities that the reporting entity has the ability to access at the measurement date;

Level 2: Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly; or

The fair value of the Company’s marketable securities of $185,395 and $221,148 as of September 30, 2019 and December 31, 2018, respectively, is valued based on Level 2 inputs. The Company’s investments consist mainly of U.S. government and agency securities, government-sponsored bond obligations and certain other corporate debt securities. Fair value is determined by taking into consideration valuations obtained from third-party pricing services. The third-party pricing services utilize industry standard valuation models, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities; issuer credit spreads; benchmark securities; and other observable inputs. The Company has assessed these as Level 2 within the fair value hierarchy of ASC 820. There were no transfers between levels within the hierarchy during the nine months ended September 30, 2019 and 2018. The Company classifies its entire investment portfolio as available for sale as defined in ASC 320, “Debt Securities.” Securities are carried at fair value with the unrealized gains (losses) reported in accumulated other comprehensive income.

The unrealized gain (loss) from marketable securities was $223 and $(199) at September 30, 2019 and December 31, 2018, respectively.

As of September 30, 2019 and December 31, 2018, none of the Company’s investments were determined to be other than temporarily impaired.

	September 30, 2019									December 31, 2018
	Amortized Cost		Unrealized Gain		Unrealized (Loss)			Estimated Fair Value		Amortized Cost		Unrealized Gain		Unrealized (Loss)			Estimated Fair Value
Commercial Paper	$	19,862	$	38	$	—		$	19,900	$	36,235	$	49	$	(1	)	$	36,283
Corporate Debt Securities		111,240		167		(7	)	$	111,400		159,348		5		(238	)		159,115
Government and Agency Securities		54,070		32		(7	)		54,095		25,764		—		(14	)		25,750
Total	$	185,172	$	237	$	(14	)	$	185,395	$	221,347	$	54	$	(253	)	$	221,148