Summary of Significant Accounting Policies - Additional Information (Details)	3 Months Ended
	Mar. 31, 2020 USD ($) Segment	Mar. 31, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | Segment	1
Available for sale debt securities credit losses	$ 0
Depreciation expense	$ 500,000	$ 400,000
Intangible assets, estimated useful life	9 years
Remeasurements to property and equipment	$ 0
Fair Value, Inputs, Level 3
Summary Of Significant Accounting Policies [Line Items]
Assets impairments charges	0	0
Otsuka U.S. Agreement
Summary Of Significant Accounting Policies [Line Items]
Cost share costs for license agreement	500,000	300,000
Reimbursable by Otsuka	300,000	200,000
Cost share costs by partner for license agreement	400,000	400,000
Reimbursable to Otsuka	$ 200,000	$ 200,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, Useful life	3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, Useful life	7 years