Income Taxes (Schedule of Federal Net Operating Losses and Tax Credit Carryforwards) (Details) - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
Operating Loss Carryforwards [Line Items]    
Net Operating Losses $ 105,077  
Research and Development Tax Credits 2,237 $ 2,450
2021-2024 [Member]    
Operating Loss Carryforwards [Line Items]    
Net Operating Losses 14,507  
2025-2037 [Member]    
Operating Loss Carryforwards [Line Items]    
Net Operating Losses 74,173  
Research and Development Tax Credits 2,237  
No Expiration [Member]    
Operating Loss Carryforwards [Line Items]    
Net Operating Losses $ 16,397