Collaborative Arrangements - GSK Platform Technology Transfer, Collaboration and License Agreement (Details) - GSK Platform $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) payment	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Liability, revenue recognized			$ 2,000
Additional milestone payments | payment	2
Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Additional contingent payments	$ 5,750
Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Additional contingent payments	38,500
Research and development revenue
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Liability, revenue recognized	$ 4,300	$ 0	$ 2,000