Annual report pursuant to Section 13 and 15(d)

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

v3.8.0.1
Fair Value Measurements - Changes in Fair Value of Financial Instruments (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Balance $ 20,941 $ 2,599  
Additions during the period 9,914 19,089  
Conversion into common shares (1,064)    
Issuance of warrants   (793)  
Loss on write off investment 250 0 $ 0
Change in fair value of investments 226 (1,071)  
Change in fair value of convertible notes 457 78  
Change in fair value of derivative liabilities (8,391) 1,039  
Balance 21,833 20,941 2,599
Contingently Issuable Warrant [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Balance 14,661 114  
Additions during the period   14,040  
Issuance of warrants   (793)  
Change in fair value of investments   0  
Change in fair value of convertible notes   0  
Change in fair value of derivative liabilities   1,300  
Balance   14,661 114
Helocyte [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Balance 4,487 0  
Additions during the period 0 4,409  
Conversion into common shares 0    
Issuance of warrants   0  
Loss on write off investment 0    
Change in fair value of investments 0 0  
Change in fair value of convertible notes 213 78  
Change in fair value of derivative liabilities 0 0  
Balance 4,700 4,487 0
Avenue [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Balance 200 0  
Additions during the period 0 200  
Conversion into common shares (299)    
Issuance of warrants   0  
Loss on write off investment 0    
Change in fair value of investments 0 0  
Change in fair value of convertible notes 99    
Change in fair value of derivative liabilities 0    
Balance 0 200 0
Caelum Convertible Notes [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Balance 0    
Additions during the period 9,914    
Conversion into common shares 0    
Loss on write off investment 0    
Change in fair value of investments 0    
Change in fair value of convertible notes 145    
Change in fair value of derivative liabilities 0    
Balance 10,059 0  
Issued Warrants [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Balance 14,661    
Additions during the period 0    
Conversion into common shares (750)    
Loss on write off investment 0    
Change in fair value of investments 0    
Change in fair value of convertible notes 0    
Change in fair value of derivative liabilities 448    
Balance 14,359 14,661  
Warrant liabilities [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Balance 179 0  
Additions during the period 0 440  
Conversion into common shares (15)    
Issuance of warrants   0  
Loss on write off investment 0    
Change in fair value of investments 0 0  
Change in fair value of convertible notes 0 0  
Change in fair value of derivative liabilities (8,839) (261)  
Balance (8,675) 179 0
Investment In Laser Device [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Balance 250 250  
Additions during the period 0 0  
Conversion into common shares 0    
Issuance of warrants   0  
Loss on write off investment (250)    
Change in fair value of investments 0 0  
Change in fair value of convertible notes 0 0  
Change in fair value of derivative liabilities 0 0  
Balance 0 250 250
Investment In Origo [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Balance 1,164 2,235  
Additions during the period 0 0  
Conversion into common shares 0    
Issuance of warrants   0  
Loss on write off investment 0    
Change in fair value of investments 226 (1,071)  
Change in fair value of convertible notes 0 0  
Change in fair value of derivative liabilities 0 0  
Balance $ 1,390 $ 1,164 $ 2,235