Stock-Based Compensation, Components of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Stock-Based Compensation Expense [Abstract]
Total stock-based compensation expense	$ 516	$ 647	$ 1,178	$ 1,505
Research and Development [Member]
Stock-Based Compensation Expense [Abstract]
Total stock-based compensation expense	134	154	403	379
General and Administrative [Member]
Stock-Based Compensation Expense [Abstract]
Total stock-based compensation expense	$ 382	$ 493	$ 775	$ 1,126