Collaboration and Research Arrangements - Other Research Agreements (Details) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue From Contract With Customer [Line Items]
Revenue recognized		$ 2,000,000	$ 2,100,000
Contract liabilities, additions		20,158,000
Multinational Pharmaceutical Company \| Other Research Agreements
Revenue From Contract With Customer [Line Items]
Revenue recognized				$ 1,100,000
GBT [Member]
Revenue From Contract With Customer [Line Items]
Contract liabilities, additions		20,000,000
GBT [Member] \| Collaboration Agreement
Revenue From Contract With Customer [Line Items]
Revenue recognized		0
Contract liabilities, additions	$ 20,000,000
Incyte
Revenue From Contract With Customer [Line Items]
Revenue recognized		2,000,000	$ 2,100,000
Contract liabilities, additions		$ 158,000
Incyte \| Collaboration Agreement
Revenue From Contract With Customer [Line Items]
Upfront payment due	20,000,000
Deferred revenue incurred	200,000
Amount offset by revenue recognition	$ 2,000,000