Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Exclusive of National Financial Instruments Measured at Fair Value on Recurring Basis (Details)

v3.20.1
Fair Value Measurements - Exclusive of National Financial Instruments Measured at Fair Value on Recurring Basis (Details) - USD ($)
$ in Thousands
Dec. 31, 2019
Dec. 31, 2018
Assets    
Fair value of investment $ 11,148  
Total 11,148  
Liabilities    
Liabilities 27 $ 10,905
Warrants [Member]    
Assets    
Fair value of investment 0  
Caelum Convertible Notes [Member]    
Assets    
Fair value of investment 0  
Fair Value, Inputs, Level 1 [Member]    
Liabilities    
Liabilities   0
Fair Value, Inputs, Level 2 [Member]    
Liabilities    
Liabilities   0
Fair Value, Inputs, Level 3 [Member]    
Assets    
Total 11,148  
Liabilities    
Liabilities 27 10,905
Caelum Convertible Notes [Member]    
Assets    
Fair value of investment 11,148  
Caelum Convertible Notes [Member] | Warrants [Member]    
Liabilities    
Liabilities 27 991
Caelum Convertible Notes [Member] | Caelum Convertible Notes [Member]    
Liabilities    
Liabilities   9,914
Caelum Convertible Notes [Member] | Fair Value, Inputs, Level 1 [Member] | Warrants [Member]    
Liabilities    
Liabilities   0
Caelum Convertible Notes [Member] | Fair Value, Inputs, Level 1 [Member] | Caelum Convertible Notes [Member]    
Liabilities    
Liabilities   0
Caelum Convertible Notes [Member] | Fair Value, Inputs, Level 2 [Member] | Warrants [Member]    
Liabilities    
Liabilities   0
Caelum Convertible Notes [Member] | Fair Value, Inputs, Level 2 [Member] | Caelum Convertible Notes [Member]    
Liabilities    
Liabilities   0
Caelum Convertible Notes [Member] | Fair Value, Inputs, Level 3 [Member]    
Assets    
Fair value of investment 11,148  
Caelum Convertible Notes [Member] | Fair Value, Inputs, Level 3 [Member] | Warrants [Member]    
Liabilities    
Liabilities $ 27 991
Caelum Convertible Notes [Member] | Fair Value, Inputs, Level 3 [Member] | Caelum Convertible Notes [Member]    
Liabilities    
Liabilities   $ 9,914