Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Derivative Contingently Issuable Warrant liabilities (Detail)

v3.8.0.1
Fair Value Measurements - Derivative Contingently Issuable Warrant liabilities (Detail) - USD ($)
$ in Thousands
 6 Months Ended 9 Months Ended
Jun. 30, 2017
Sep. 30, 2017
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Conversion into common shares   $ (1,064)
National [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Fair value at the beginning of period: $ 14,359 14,359
Change in fair value (5,527)  
Fair value at end of period: 8,832  
Avenue [Member] | Convertible Debt [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Fair value at the beginning of period: 200 200
Conversion into common shares   (299)
Change in fair value   99
Fair value at end of period:   0
Avenue [Member] | Contingently Issuable Warrants [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Fair value at the beginning of period: 302 302
Conversion into common shares   (750)
Change in fair value   448
Fair value at end of period:   0
Avenue [Member] | Warrant [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Fair value at the beginning of period: 12 12
Conversion into common shares   (15)
Change in fair value   3
Fair value at end of period:   0
Helocyte [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Fair value at the beginning of period: 167 167
Change in fair value   (79)
Fair value at end of period:   88
Helocyte [Member] | Convertible Debt [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Fair value at the beginning of period: 4,487 4,487
Change in fair value   246
Fair value at end of period:   4,733
Caelum Warrant Liabilities [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Fair value at the beginning of period: 0 0
Change in fair value   225
Fair value at end of period:   225
Caelum Convertible Notes [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Fair value at the beginning of period: $ 0 0
Additions   9,914
Change in fair value   14
Fair value at end of period:   $ 9,928