Short-Term Investments

3 Months Ended

Mar. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Short-Term Investments

Short-Term Investments

The Company invests in marketable securities consisting of debt instruments of the U.S. Government, and financial institutions and corporations with strong credit ratings. The following represents a summary of the estimated fair value of short-term investments as of March 31, 2020 and December 31, 2019 (in thousands):

At March 31, 2020	Maturity (in years)	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Estimated Fair Value
Available-for-sale securities:
Commercial paper	Less than 1	$	17,352	$	11	$	—		$	17,363
U.S. Government-sponsored enterprise	Less than 2	20,255		63		—			20,318
U.S. Treasury securities	Less than 1	12,721		93		—			12,814
Corporate debt securities	Less than 2	35,251		39		(62		)	35,228
Total		$	85,579	$	206	$	(62	)	$	85,723

At December 31, 2019	Maturity (in years)	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Estimated Fair Value
Available-for-sale securities:
Commercial paper	Less than 1	$	24,147	$	10	$	—		$	24,157
U.S. Government-sponsored enterprise	Less than 2	33,073		26		—			33,099
U.S. Treasury securities	Less than 2	17,963		17		(1		)	17,979
Corporate debt securities	Less than 2	50,011		42		(5		)	50,048
Total		$	125,194	$	95	$	(6	)	$	125,283

The Company has classified all marketable securities, regardless of maturity, as short-term investments based upon the Company’s ability and intent to use any of those marketable securities to satisfy the Company’s liquidity requirements.

The Company periodically reviews the portfolio of available-for-sale debt securities to determine if any investment is impaired due to changes in credit risk or other potential valuation concerns. Unrealized losses on available-for-sale debt securities at March 31, 2020 were not significant and were due to changes in interest rates, including credit spreads from perceived increased credit risks as a result of the novel coronavirus (COVID-19) global pandemic. The Company does not intend to sell the available-for-sale debt securities that are in an unrealized loss position, and it is not more likely than not that the Company will be required to sell these debt securities before recovery of their amortized cost bases, which may be at maturity. Based on the credit quality of the available-for-sale debt securities that are in an unrealized loss position, and the Company’s estimates of future cash flows to be collected from those securities, the Company believes the unrealized losses are not credit losses. Accordingly, at March 31, 2020, the Company has not recorded an allowance for credit losses related to its available-for-sale debt securities.