Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - 2018 Equity Inducement Plan and 2016 Employee Stock Purchase Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Employees
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 7,111	$ 8,038	$ 6,220
Non-Employees
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	0	0	36
Research and Development | Employees
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	2,591	2,723	2,168
Research and Development | Non-Employees
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	0	0	36
General and Administrative | Employees
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	4,520	5,315	4,052
General and Administrative | Non-Employees
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 0	$ 0	$ 0