Licenses, Asset Acquisitions and Contingent Consideration - Schedule of IPR&D Expense (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Acquired Finite-Lived Intangible Assets [Line Items]
Total in process research and development	$ 20,000	$ 15	$ 15,000	$ 45	$ 17,805
GB004
Acquired Finite-Lived Intangible Assets [Line Items]
Total in process research and development		0	15,000	0	15,000
Other preclinical programs
Acquired Finite-Lived Intangible Assets [Line Items]
Total in process research and development		$ 15	$ 0	$ 45	$ 2,805