Stockholders Equity (Stock-based Compensation Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Total stock-based compensation expense	$ 568	$ 2,283
General and administrative
Total stock-based compensation expense	436	700
Research and development
Total stock-based compensation expense	$ 132	$ 1,583