Significant Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) item	Dec. 31, 2022 USD ($)
Operating segment | item	1
Letters of credit | item	2
Impairment of long-lived assets	$ 0	$ 0
Impairment of in-process research and development	0	0
Impairment Loss	0	0
Other receivables	3,363	8,531
Long-lived assets	12,559	3,617
UNITED STATES
Long-lived assets	$ 12,400
Percentage of long-lived assets	98.80%
Grant [Member]
Other receivables	$ 1,500	$ 1,900