XML 56 R37.htm IDEA: XBRL DOCUMENT v3.24.1
Summary of Significant Accounting Policies (Narrative) (Details)
 12 Months Ended
Dec. 31, 2023
USD ($)
segment
country
Dec. 31, 2022
USD ($)
Dec. 31, 2023
GBP (£)
country
Accounting Policies [Line Items]      
Cash and cash equivalents $ 3,378,000 $ 18,345,000  
Cash exceeding balance insured by FDIC 2,400,000    
Cash balance insured by FSCS | £     £ 85,000
Cash exceeding balance insured by FSCS $ 600,000    
Number of operating segments | segment 1    
Number of reportable segments | segment 1    
Number of geographic areas for development operations | country 2   2
Revenues $ 420,000 0  
Reclassifications out of other comprehensive income (loss) $ 0 $ 0  
Board Director [Member]      
Accounting Policies [Line Items]      
Stock awards vesting period 1 year    
Minimum      
Accounting Policies [Line Items]      
Stock awards vesting period 3 years    
Maximum      
Accounting Policies [Line Items]      
Cash balances insured by FDIC $ 250,000    
Stock awards vesting period 4 years    
Property, plant and equipment | Minimum      
Accounting Policies [Line Items]      
Estimated useful life 3 years   3 years
Property, plant and equipment | Maximum      
Accounting Policies [Line Items]      
Estimated useful life 5 years   5 years
Leasehold improvements | Minimum      
Accounting Policies [Line Items]      
Estimated useful life 2 years 2 years 2 years
Leasehold improvements | Maximum      
Accounting Policies [Line Items]      
Estimated useful life 5 years 5 years 5 years