Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Outstanding Warrants Valuation Assumption (Detail)

v3.19.1
Stockholders' Equity - Outstanding Warrants Valuation Assumption (Detail)
Dec. 31, 2018
$ / shares
Dec. 31, 2017
$ / shares
Measurement Input, Risk Free Interest Rate    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Warrants and Rights Outstanding, Measurement Input 0.026 0.019
Measurement Input, Expected Term    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Expected life (in years) 1 year 1 month 6 days 2 years 1 month 6 days
Measurement Input, Expected Dividend Rate    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Warrants and Rights Outstanding, Measurement Input 0.00 0.00
Measurement Input, Price Volatility    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Warrants and Rights Outstanding, Measurement Input 0.77 1.03
Measurement Input, Share Price    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Warrants and Rights Outstanding, Measurement Input 4.04 10.02