Collaboration and License Agreements and Supply Agreements - Summary of Recognized Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	$ 61,880	$ 42,722	$ 42,736
Collaboration and License Agreements and Supply Agreements
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	61,880	42,722	42,736
Collaboration and License Agreements and Supply Agreements | Bristol-Myers Squibb Company ("BMS")
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	11,483	11,407	11,321
Collaboration and License Agreements and Supply Agreements | Merck Sharp & Dohme Corporation ("Merck")
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	42,780	26,075	21,458
Collaboration and License Agreements and Supply Agreements | Merck KGaA, Darmstadt, Germany "EMD Serono")
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	4,576	5,042	8,879
Collaboration and License Agreements and Supply Agreements | Vaxcyte, Inc.
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	3,041	198	1,078
BMS Agreement and the 2018 BMS Master Services Agreement
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Revenues	11,483	11,407	11,321
BMS Agreement and the 2018 BMS Master Services Agreement | Ongoing Performance Related to Unsatisfied Performance Obligations
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Revenues		2,974	3,936
BMS Agreement and the 2018 BMS Master Services Agreement | Research and Development Services
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Revenues	940	646	571
BMS Agreement and the 2018 BMS Master Services Agreement | Materials Supply
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Revenues	10,543	7,787	6,814
2020 Merck Master Services Agreement
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	42,780	26,075	21,458
2020 Merck Master Services Agreement | Ongoing Performance Related to Unsatisfied Performance Obligations
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	35,098	18,474	14,736
2020 Merck Master Services Agreement | Research and Development Services
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	2,666	5,485	3,578
2020 Merck Master Services Agreement | Financing Component on Unearned Revenue
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	610	1,852	3,144
2020 Merck Master Services Agreement | Materials Supply
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	4,406	264
2019 EMD Serono Supply Agreement
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	4,576	5,042	8,879
2019 EMD Serono Supply Agreement | Ongoing Performance Related to Unsatisfied Performance Obligations
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue			2,266
2019 EMD Serono Supply Agreement | Contingent Payment / Milestone Earned
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	2,000	1,000	1,500
2019 EMD Serono Supply Agreement | Research and Development Services
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	851	1,316	2,890
2019 EMD Serono Supply Agreement | Materials Supply
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	1,725	2,726	2,223
Supply Agreement | Vaxcyte, Inc.
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	3,041	198	1,078
Supply Agreement | Vaxcyte, Inc. | Research and Development Services
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	1,131	184
Supply Agreement | Vaxcyte, Inc. | Materials Supply
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Total revenue	$ 1,910	$ 14	$ 1,078