Collaboration and License Agreements - Collaboration Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 26,024	$ 15,198	$ 82,472	$ 64,374
Licenses
Disaggregation of Revenue [Line Items]
Revenue	0	0	0	15,000
On-going research and development services
Disaggregation of Revenue [Line Items]
Revenue	4,695	7,504	29,915	23,698
Development activities
Disaggregation of Revenue [Line Items]
Revenue	0	312	0	902
Commercialization activities
Disaggregation of Revenue [Line Items]
Revenue	821	916	2,499	2,878
Collaboration revenue – related party
Disaggregation of Revenue [Line Items]
Revenue	$ 5,516	$ 8,732	$ 32,414	$ 42,478

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration