Nature of the Business and Basis of Presentation (Details) $ / shares in Units, $ in Thousands	Mar. 18, 2021 USD ($) $ / shares shares	Nov. 26, 2019 USD ($) $ / shares	Apr. 12, 2019 USD ($) $ / shares	Mar. 13, 2019	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Restructuring Cost and Reserve [Line Items]
Cash and cash equivalents						$ 78,708	$ 126,184	$ 8,134	$ 26,684
Accumulated deficit						$ 194,175	$ 132,044
Sale price (in dollars per share) | $ / shares		$ 12.00	$ 11.00
Percentage of voting interest				64.00%
Proceeds from common stock issuance		$ 65,000	$ 85,800
Forecast
Restructuring Cost and Reserve [Line Items]
Limited partners' contributed capital					$ 65,000
Subsequent Event
Restructuring Cost and Reserve [Line Items]
Sale price (in dollars per share) | $ / shares	$ 8.70
Proceeds from common stock issuance	$ 55,000
Subsequent Event | Private Placement
Restructuring Cost and Reserve [Line Items]
Common stock, reserved for future issuance (in shares) | shares	229,885
Sale price (in dollars per share) | $ / shares	$ 8.70
Arsanis
Restructuring Cost and Reserve [Line Items]
Exchange ratio				0.5702