Fair Value of Financial Instruments - Summary of Fair Value of Financial Instrument (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets:
Money market funds	$ 61,564	$ 94,631
Total short-term investments	236,655	218,221
Total	298,219	312,852
Commercial Paper
Assets:
Total short-term investments	60,462	63,445
Corporate Debt Securities
Assets:
Total short-term investments	55,299	48,614
U.S. Government Securities
Assets:
Total short-term investments	120,894	106,162
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Money market funds	61,564	94,631
Total	61,564	94,631
Significant Other Observable Inputs (Level 2)
Assets:
Total short-term investments	236,655	218,221
Total	236,655	218,221
Significant Other Observable Inputs (Level 2) | Commercial Paper
Assets:
Total short-term investments	60,462	63,445
Significant Other Observable Inputs (Level 2) | Corporate Debt Securities
Assets:
Total short-term investments	55,299	48,614
Significant Other Observable Inputs (Level 2) | U.S. Government Securities
Assets:
Total short-term investments	$ 120,894	$ 106,162