Commitments and Contingencies - Additional Information (Details) ft² in Thousands, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) officer	Aug. 31, 2015 ft²
Commitments And Contingencies [Line Items]
Weighted average discount rate, operating lease liabilities	9.85%
Weighed average remaining lease term, operating leases	6 years 3 months
Rentable square feet of facility space | ft²				51,000
Optional term of extending lease agreement				5 years
Current contractual base rent payments per month	$ 95
Percentage of increase in annual rental payments	3.00%
Rent expense associated with primary facility lease (Topic 842)	$ 224	$ 157
February 2020 Restructuring
Commitments And Contingencies [Line Items]
Accrued severance costs	50
Employee severance costs expensed	59
Two Former Officers
Commitments And Contingencies [Line Items]
Number of former officers | officer			2
Severance expenses	$ 0	$ 878
Accrued severance costs			$ 33