Commitments and Contingencies (Details) $ in Millions	Dec. 31, 2020 USD ($)
In-process and future manufacturing of antibody and cytotoxic agents
Collaborations and Manufacturing Commitments
Noncancelable obligations under several agreements	$ 6.5
Minimum
Collaborations and Manufacturing Commitments
Manufacturing commitment	$ 36.0

Amount of recorded unconditional purchase obligation to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121559207&loc=d3e25383-109308

Name:	us-gaap_RecordedUnconditionalPurchaseObligationDueWithinOneYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant