Cash, Cash Equivalents and Marketable Securities - Summary of Cash, Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized cost	$ 108,522	$ 187,750
Cash and cash equivalents, Estimated Fair Value	108,522	187,750
Marketable securities, Amortized cost	96,250	62,619
Marketable securities, Unrealized gains	11	6
Marketable securities, Unrealized losses	(9)	(3)
Marketable securities, Estimated Fair Value	96,252	62,622
Cash
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized cost	21,548	5,659
Cash and cash equivalents, Estimated Fair Value	21,548	5,659
Money Market Funds
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized cost	81,974	113,592
Cash and cash equivalents, Estimated Fair Value	81,974	113,592
Certificates of Deposit
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized cost		157
Cash and cash equivalents, Estimated Fair Value		157
Commercial Paper
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized cost	5,000	40,844
Cash and cash equivalents, Estimated Fair Value	5,000	40,844
Marketable securities, Amortized cost	45,479	35,089
Marketable securities, Unrealized gains	2
Marketable securities, Unrealized losses	(3)
Marketable securities, Estimated Fair Value	45,478	35,089
U.S. Government and Agency Securities
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized cost		27,498
Cash and cash equivalents, Estimated Fair Value		27,498
Marketable securities, Amortized cost	37,155	26,026
Marketable securities, Unrealized gains	9	6
Marketable securities, Unrealized losses		(3)
Marketable securities, Estimated Fair Value	37,164	26,029
Corporate Debt Securities
Cash And Cash Equivalents [Line Items]
Marketable securities, Amortized cost	13,616	1,504
Marketable securities, Unrealized losses	(6)
Marketable securities, Estimated Fair Value	$ 13,610	$ 1,504