Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Details)

v3.19.2
Fair Value Measurements - Additional Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Gain (loss) due to change in value of note payable $ (7) $ (64) $ (7) $ (81)
VenturEast | BioServe        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Number of shares associated with notes payable (in shares)     84,278  
Gain (loss) due to change in value of note payable 7 64 $ 7 81
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 $ 206 $ 2,154 $ 199 $ 2,846