Collaboration and License Agreements and Supply Agreements - Summary of Recognized Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	$ 14,660	$ 7,152
Collaboration and License Agreements and Supply Agreements
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	14,660	7,152
Collaboration and License Agreements and Supply Agreements | Bristol-Myers Squibb Company ("BMS")
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	1,239	2,045
Collaboration and License Agreements and Supply Agreements | Merck
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	11,883	2,777
Collaboration and License Agreements and Supply Agreements | Merck KGaA, Darmstadt, Germany "EMD Serono")
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	220	2,294
Collaboration and License Agreements and Supply Agreements | Vaxcyte
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	$ 1,318	$ 36