Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Schedule of Financial Instruments, Measured at Fair Value on a Recurring Basis) (Details)

v3.21.1
Fair Value Measurements (Schedule of Financial Instruments, Measured at Fair Value on a Recurring Basis) (Details) - USD ($)
$ in Thousands
Mar. 31, 2021
Dec. 31, 2020
Assets    
Assets, fair value $ 23,479 $ 17,566
Liabilities    
Liabilities, fair value 362  
Caelum [Member]    
Assets    
Assets, fair value 23,479 17,566
Warrants [Member]    
Liabilities    
Liabilities, fair value 362  
Level 1 [Member]    
Assets    
Assets, fair value 0  
Liabilities    
Liabilities, fair value 0  
Level 1 [Member] | Caelum [Member]    
Assets    
Assets, fair value 0  
Level 1 [Member] | Warrants [Member]    
Liabilities    
Liabilities, fair value 0  
Level 2 [Member]    
Assets    
Assets, fair value 0  
Liabilities    
Liabilities, fair value 0  
Level 2 [Member] | Caelum [Member]    
Assets    
Assets, fair value 0  
Level 2 [Member] | Warrants [Member]    
Liabilities    
Liabilities, fair value 0  
Level 3 [Member]    
Assets    
Assets, fair value 23,479 17,566
Liabilities    
Liabilities, fair value 362  
Level 3 [Member] | Caelum [Member]    
Assets    
Assets, fair value 23,479 $ 17,566
Level 3 [Member] | Warrants [Member]    
Liabilities    
Liabilities, fair value $ 362