Annual report pursuant to Section 13 and 15(d)

Derivative Liability and Fair Value Measurements (Estimate the fair value of warrants outstanding) (Detail)

v3.19.1
Derivative Liability and Fair Value Measurements (Estimate the fair value of warrants outstanding) (Detail)
12 Months Ended
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Assumptions for Pricing Model:      
Expected annual dividends 0.00% 0.00% 0.00%
Value of warrants outstanding:      
Fair value of warrants $ 0 $ 152,927 $ 173,131
Measurement Input, Expected Term [Member]      
Assumptions for Pricing Model:      
Derivative Liability, Measurement Input 0 0.59 1.22
Measurement Input, Price Volatility [Member]      
Assumptions for Pricing Model:      
Derivative Liability, Measurement Input 0 143 100
Measurement Input, Risk Free Interest Rate [Member]      
Assumptions for Pricing Model:      
Derivative Liability, Measurement Input 0 1.76 1.47
Monte Carlo Options Lattice Pricing Model Warrants Outstanding      
Assumptions for Pricing Model:      
Expected annual dividends 0.00% 0.00% 0.00%