Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Warrant liabilities and Convertible Notes (Detail)

v3.20.1
Fair Value Measurements - Warrant liabilities and Convertible Notes (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Issuance of warrant due to conversion of note $ (991)  
Conversion of the convertible notes   $ (437)
Warrants [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Issuance of warrant due to conversion of note (991)  
Caelum Convertible Notes [Member] | Convertible Debt [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Beginning balance 9,914 10,059
Change in fair value of derivative liabilities   (145)
Conversion of the convertible notes (9,914)  
Ending balance 0 9,914
Caelum Convertible Notes [Member] | Warrants [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Beginning balance 991 222
Change in fair value of derivative liabilities   769
Issuance of warrant due to conversion of note (991)  
Ending balance 0 $ 991
Cyprium [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Issuance of warrant due to conversion of note 27  
Ending balance $ 27