Stock-Based Compensation - Schedule of Stock-Based Compensation Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 183	$ 185	$ 430	$ 440
Research and Development
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	31	61	112	175
General and Administrative
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 152	$ 124	$ 318	$ 265