Quarterly report pursuant to Section 13 or 15(d)

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

v3.10.0.1
Fair Value Measurements - Warrant Liabilities And Convertible Notes At Fair Value (Detail) - $ / shares
 5 Months Ended 6 Months Ended
Mar. 15, 2018
Jun. 30, 2018
Mar. 31, 2018
Warrants Issuable [Member]      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Risk-free interest rate 2.42%    
Expected dividend yield 0.00%    
Expected term in years 3 years 5 months 26 days    
Expected volatility 59.23%    
National Warrant Liabilities [Member]      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Expected dividend yield     0.00%
National Warrant Liabilities [Member] | Minimum [Member]      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Risk-free interest rate   1.89% 1.63%
Expected term in years     2 months 5 days
Strike price     $ 0.01
Remaining volatility     56.40%
National Warrant Liabilities [Member] | Maximum [Member]      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Risk-free interest rate   2.37% 2.56%
Expected term in years     4 years 1 month 10 days
Strike price     $ 10.00
Remaining volatility     386.10%
Caelum Convertible Notes [Member]      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Expected dividend yield   0.00%  
Expected volatility   53.00%  
Caelum Convertible Notes [Member] | Minimum [Member]      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Expected term in years   2 months 16 days  
Caelum Convertible Notes [Member] | Maximum [Member]      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Expected term in years   1 year 2 months 16 days