Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Warrant Liabilities And Convertible Notes At Fair Value (Detail)

v3.8.0.1
Fair Value Measurements - Warrant Liabilities And Convertible Notes At Fair Value (Detail) - $ / shares
 6 Months Ended 9 Months Ended
Jun. 30, 2017
Sep. 30, 2017
Warrants Issuable [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Risk-free interest rate 1.89%  
Expected dividend yield 0.00%  
Expected term in years 4 years 2 months 12 days  
Expected volatility 91.00%  
Helocyte [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Expected dividend yield   0.00%
Expected volatility   70.00%
Strike price   $ 0.44
Helocyte [Member] | Convertible Debt [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Expected dividend yield   0.00%
Expected volatility   59.50%
Helocyte [Member] | Minimum [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Risk-free interest rate   1.733%
Expected term in years   3 years 9 months
Helocyte [Member] | Minimum [Member] | Convertible Debt [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Risk-free interest rate   1.199%
Expected term in years   6 months
Helocyte [Member] | Maximum [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Risk-free interest rate   1.795%
Expected term in years   4 years 2 months 1 day
Helocyte [Member] | Maximum [Member] | Convertible Debt [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Risk-free interest rate   1.336%
Expected term in years   1 year 1 month 28 days
Caelum Warrant Liabilities [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Expected dividend yield   0.00%
Expected volatility   70.00%
Strike price   $ 1.43
Caelum Warrant Liabilities [Member] | Minimum [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Risk-free interest rate   1.895%
Expected term in years   4 years 10 months 2 days
Caelum Warrant Liabilities [Member] | Maximum [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Risk-free interest rate   1.914%
Expected term in years   4 years 11 months 16 days
Caelum Convertible Notes [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Expected dividend yield   0.00%
Expected volatility   70.00%
Caelum Convertible Notes [Member] | Minimum [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Risk-free interest rate   1.246%
Expected term in years   8 months 16 days
Caelum Convertible Notes [Member] | Maximum [Member]    
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]    
Risk-free interest rate   1.463%
Expected term in years   1 year 11 months 12 days