License, Collaboration, and Funding Agreements - Research and Development Incentive Program (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Other income	$ 905	$ 517	$ 0
Research and Development Incentive Program
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Amount due under incentive receivable plan	900
Other income	494
Abbisko Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential milestone payments receivable	$ 208,000
X4 Austria
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Reimbursement rate for research and development	0.14