Collaborative Arrangement (Details) - USD ($)	10 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Remaining fixed consideration to be received	$ 3,000,000.0	$ 3,000,000.0
Collaboration revenue		3,648,000	$ 0	$ 0
Deferred revenue	13,400,000	$ 13,400,000
Revenue recognized	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Minimum
Disaggregation of Revenue [Line Items]
Period over which recognition of collaboration revenue is expected	3 years	3 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Maximum
Disaggregation of Revenue [Line Items]
Period over which recognition of collaboration revenue is expected	4 years	4 years
Fixed-price Contract
Disaggregation of Revenue [Line Items]
Payment due for collaborative agreement					$ 20,000,000.0
Payment made toward collaborative agreement	$ 17,000,000.0
Period over which remainder of payment will be made	2 years
Variable Consideration Priced Contract | Upon Achievement of Regulatory Milestones
Disaggregation of Revenue [Line Items]
Additional amount that can be earned upon achievement of regulatory milestones	$ 66,000,000.0	$ 66,000,000.0
Variable Consideration Priced Contract | Upon Achievement of Net Sales Milestones
Disaggregation of Revenue [Line Items]
Additional amounts that could be earned by achievement of net sales milestones	$ 42,500,000	$ 42,500,000