Development Derivative Liability - Roll Forward (Details) - Derivative Liability $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Initial payment, net of common stock warrants	$ 2,100
Funding during the period	37,100
Change in fair value	12,500
SFJ Agreement | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0
Initial payment, net of common stock warrants	2,075
Funding during the period	37,137
Change in fair value	12,507
Ending balance	$ 51,719