Marketable Securities

9 Months Ended

Sep. 30, 2020

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

Marketable Securities

Available-for-sale marketable securities and cash and cash equivalents as of September 30, 2020 and December 31, 2019 consisted of the following (in thousands):

	September 30, 2020
	Amortized Cost Value		Gross  Unrealized  Gains		Gross  Unrealized  Losses		Fair Value
Cash and cash equivalents:
Cash	$	55,796	$	—	$	—	$	55,796
Money market funds	26,034		—		—		26,034
Total	$	81,830	$	—	$	—	$	81,830
Marketable securities:
Domestic corporate debt securities	$	38,822	$	91	$	(3)	$	38,910
Domestic corporate commercial paper	4,968		—		(5)		4,963
Total	$	43,790	$	91	$	(8)	$	43,873

	December 31, 2019
	Amortized Cost Value		Gross  Unrealized  Gains		Gross  Unrealized  Losses		Fair Value
Cash and cash equivalents:
Cash	$	34,726	$	—	$	—	$	34,726
Money market funds	35,160		—		—		35,160
Total	$	69,886	$	—	$	—	$	69,886
Marketable securities:
Domestic corporate debt securities	$	41,229	$	3	$	(3)	$	41,229
Domestic corporate commercial paper	24,900		5		—		24,905
Agency bonds	12,391		1		(3)		12,389
US treasury bonds	12,492		—		—		12,492
Total	$	91,012	$	9	$	(6)	$	91,015

The Company reviews marketable securities whenever the fair value of an investment is less than the amortized cost and evidence indicates that an investment’s carrying amount is not recoverable within a reasonable period of time. We evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, we consider the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded for the credit loss on the condensed consolidated balance sheet, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that is not related to credit is recognized in other comprehensive income.

Changes in the allowance for credit losses are recorded as a provision for (or reversal of) credit loss expense on the condensed consolidated statement of operations. Losses are charged against the allowance when the Company believes the uncollectability of an available-for-sale debt security is confirmed or when either of the criteria regarding intent or requirement to sell is met. The unrealized losses at September 30, 2020 and December 31, 2019 are attributable to changes in interest rates and the Company does not believe any unrealized losses represent credit losses.

As of September 30, 2020 and December 31, 2019, the Company had 2 and 8 available-for-sale debt securities in an unrealized loss position, respectively, for which an allowance for credit losses has not been recorded. The following table summarizes such investments by major security type and length of time in a continuous unrealized loss position as of September 30, 2020 (in thousands).

	Less than 12 Months				12 months or longer		Total
	Fair value		Unrealized losses		Fair value	Unrealized losses	Fair value		Unrealized losses
Available-for-sale debt securities
Domestic corporate debt securities	$	4,621	$	(3)	—	—	$	4,621	$	(3)
Domestic corporate commercial paper	4,964		(5)		—	—	4,964		(5)
Total available-for-sale debt securities	$	9,585	$	(8)	—	—	$	9,585	$	(8)