Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Details)

v3.20.2
Fair Value Measurements - Additional Information (Details)
$ / shares in Units, shares in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2020
USD ($)
$ / shares
Jun. 30, 2019
USD ($)
Jun. 30, 2020
USD ($)
installment
$ / shares
shares
Jun. 30, 2019
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Gain due to change in value of note payable $ 0 $ (7,000) $ (4,000) $ (7,000)
VenturEast | BioServe        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Number of shares associated with notes payable (in shares) | shares     3  
Shares issued, price per share (usd per share) | $ / shares $ 4.20   $ 4.20  
Number of payments | installment     2  
Settlement payment amount     $ 50,000  
Gain due to change in value of note payable $ 0 7,000 4,000 7,000
2016 Offering | Significant Unobservable Inputs (Level 3) | Fair Value Measurements, Recurring        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Gain on derivative due to change in stock price $ 25,000 $ 206,000 $ 152,000 $ 199,000