Investments

6 Months Ended

Jun. 30, 2021

Investments, Debt and Equity Securities [Abstract]

Investments

Investments

The following tables summarize the Company's debt investments (in thousands):

	June 30, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Corporate bonds	$	40,821	$	2	$	(11)	$	40,812
U.S. treasury securities	15,554		1		(8)		15,547
Commercial paper	57,755		6		(1)		57,760
Total investments	$	114,130	$	9	$	(20)	$	114,119
	December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Corporate bonds	$	3,256	$	2	$	—	$	3,258
U.S. treasury securities	28,717		1		(3)		28,715
Total investments	$	31,973	$	3	$	(3)	$	31,973

The following tables summarize the Company's debt investments with unrealized losses, aggregated by investment type and the length of time that individual investments have been in a continuous unrealized loss position (in thousands, except number of securities):

	June 30, 2021
	Less than 12 Months				Greater than 12 Months				Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Corporate bonds	$	30,714	$	(11)	$	—	$	—	$	30,714	$	(11)
Commercial paper	10,493		(1)		—		—		10,493		(1)
U.S. treasury securities	4,992		(8)		—		—		4,992		(8)
Total	$	46,199	$	(20)	$	—	$	—	$	46,199	$	(20)
Number of securities with unrealized losses			16				—				16
	December 31, 2020
	Less than 12 Months				Greater than 12 Months				Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
U.S. treasury securities	$	16,598	$	(3)	$	—	$	—	$	16,598	$	(3)
Total	$	16,598	$	(3)	$	—	$	—	$	16,598	$	(3)
Number of securities with unrealized losses			6				—				6

The Company periodically reviews available-for-sale debt investments for other-than-temporary declines in fair value below the cost basis and whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The Company evaluates, among other things, the duration and extent to which the fair value of a security is less than its cost; the financial condition of the issuer and any changes thereto; and the Company’s intent to sell, or whether it will more likely than not be required to sell, the security before recovery of its cost basis. At June 30, 2021, the Company did not intend to sell, and was not more likely than not to be required to sell, the available-for-sale debt investments in an unrealized loss position before recovery of the cost basis of the securities, which may be at maturity. There were no such declines in value for the three and six months ended June 30, 2021 and 2020. Unrealized gains and losses on debt investments are recorded to unrealized (loss) gain on debt investments, net in the Consolidated Statements of Operations and Comprehensive Loss. Realized gains and losses on debt investments are recorded based on specific identification to interest income and other, net in the Consolidated Statements of Operations and Comprehensive Loss. The Company recognizes interest income on an accrual basis in interest income in the Consolidated Statements of Operations and Comprehensive Loss.

The following table summarizes the scheduled maturity for the Company's debt investments at June 30, 2021 (in thousands):

Maturing in one year or less	$	106,584
Maturing after one year through two years	7,535
Total debt investments	$	114,119