Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Changes in Fair Value of Financial Instruments (Detail)

v3.20.1
Fair Value Measurements - Changes in Fair Value of Financial Instruments (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Balance $ 10,905 $ 21,833
Payment of convertible note   (4,408)
Disposal of National   5,375
Conversion of convertible notes (9,914)  
Change in fair value of investments   (1,390)
Conversion of the convertible notes   (437)
Change in fair value of derivative liabilities   682
Balance 11,175 10,905
Helocyte [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Balance 0 4,700
Payment of convertible note   (4,408)
Disposal of National   0
Change in fair value of investments   0
Conversion of the convertible notes   (292)
Change in fair value of derivative liabilities   0
Balance   0
Caelum Convertible Notes [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Balance 9,914 10,059
Payment of convertible note   0
Disposal of National   0
Change in fair value of investments   0
Conversion of the convertible notes   (145)
Change in fair value of derivative liabilities   0
Balance   9,914
Warrants National [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Balance 0 5,597
Payment of convertible note   0
Disposal of National   5,597
Change in fair value of investments   0
Conversion of the convertible notes   0
Change in fair value of derivative liabilities   0
Balance   0
Warrants [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Balance 991 87
Payment of convertible note   0
Disposal of National   (222)
Change in fair value of investments   0
Conversion of the convertible notes   0
Change in fair value of derivative liabilities   682
Balance   991
Investment In Origo [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Balance $ 0 1,390
Payment of convertible note   0
Disposal of National   0
Change in fair value of investments   (1,390)
Conversion of the convertible notes   0
Change in fair value of derivative liabilities   0
Balance   $ 0