Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

Financial Assets Measured at Fair Value on a Recurring Basis

Financial assets measured at fair value on a recurring basis using the above input categories were as follows (in thousands):

	Pricing Category	Fair Value at
		March 31, 2022		December 31, 2021
Assets:
Cash equivalents and marketable securities:
Money market funds	Level 1	$	36,380	$	102,978
U.S. Treasury securities	Level 1	—		49,996
Short-term investments:
U.S. Treasury securities	Level 1	465,370		330,053
Corporate debt securities	Level 2	85,951		160,914
Total		$	587,701	$	643,941

Summary of Cash Equivalents and Marketable Securities

The following is a summary of cash equivalents and marketable securities as of March 31, 2022 (in thousands):

	Amortized Cost		Unrealized Losses		Estimated Fair Value
Cash equivalents:
Money market funds	$	36,380	$	—	$	36,380
Short-term investments:
U.S. Treasury securities	467,564		(2,194)		$	465,370
Corporate debt securities	85,986		(35)		$	85,951
Total	$	589,930	$	(2,229)	$	587,701

The following is a summary of cash equivalents and marketable securities as of December 31, 2021 (in thousands):

	Amortized Cost		Unrealized Losses		Estimated Fair Value
Cash equivalents:
Money market funds	$	102,978	$	—	$	102,978
U.S. Treasury securities	49,996		—		49,996
Short-term investments:
U.S. Treasury securities	330,618		(565)		$	330,053
Corporate debt securities	160,937		(23)		$	160,914
Total	$	644,529	$	(588)	$	643,941

Contractual Maturities of Short-Term Investments

The contractual maturities of short-term investments are as follows (in thousands):

	March 31, 2022		December 31, 2021
Due within one year	$	353,333	$	291,525
Due after one year to two years	197,987		199,442
Total	$	551,320	$	490,967