Acquisition - Patent License Acquisition (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Business Acquisition [Line Items]
Finite-lived intangible assets		$ 16,986		$ 16,986		$ 7,600
In process research and development expensed				8,500	$ 0
Capitalized license fees		55		55		6,890
Amortization of intangible assets		500	$ 200	$ 800	200
Minimum
Business Acquisition [Line Items]
Useful life (years)				6 years
Maximum
Business Acquisition [Line Items]
Useful life (years)				12 years
Patent and Covenant Rights | Minimum
Business Acquisition [Line Items]
Useful life (years)	6 years
Patent and Covenant Rights | Maximum
Business Acquisition [Line Items]
Useful life (years)	12 years
Acquired license
Business Acquisition [Line Items]
Finite-lived intangible assets		11,886		$ 11,886		$ 5,100
KeyGene Patent License Acquisition
Business Acquisition [Line Items]
Payment in connection with a license agreement	$ 18,500
Asset acquisition, transaction costs	600
In process research and development expensed	8,500
Settlement of prior dispute between parties	1,200
KeyGene Patent License Acquisition | Patent and Covenant Rights
Business Acquisition [Line Items]
Finite-lived intangible assets	$ 9,400
KeyGene Patent License Acquisition | Acquired license
Business Acquisition [Line Items]
Amortization of intangible assets		$ 0	$ 200		$ 500