v3.19.1
Notes Payable - Schedule of Notes Payable (Parenthetical) (Detail) - Notes Payable [Member]
3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Sep. 30, 2018
Aug. 31, 2017
8% Secured Promissory Notes Due August 2018 [Member]        
Debt Instrument [Line Items]        
Notes payable, interest rate 8.00% 8.00%   8.00%
Notes payable, maturity date Aug. 31, 2018 Aug. 31, 2018    
0% Convertible Notes Due January 2021 [Member]        
Debt Instrument [Line Items]        
Notes payable, interest rate 0.00% 0.00%    
Notes payable, maturity date Jan. 31, 2021 Jan. 31, 2021    
4% Promissory Note Due April 2021 [Member]        
Debt Instrument [Line Items]        
Notes payable, interest rate 4.00% 4.00%    
Notes payable, maturity date Apr. 30, 2021 Apr. 30, 2021    
0% Promissory Note Due April 2019 [Member]        
Debt Instrument [Line Items]        
Notes payable, interest rate 0.00% 0.00%    
Notes payable, maturity date Apr. 30, 2019 Apr. 30, 2019    
8% Promissory Note Due March 2021 [Member]        
Debt Instrument [Line Items]        
Notes payable, interest rate 8.00% 8.00% 8.00%  
Notes payable, maturity date Mar. 31, 2021 Mar. 31, 2021    
12% Convertible Notes Due October 2019 [Member]        
Debt Instrument [Line Items]        
Notes payable, interest rate 12.00% 12.00%    
Notes payable, maturity date Oct. 31, 2019 Oct. 31, 2019    
12% Convertible Notes Due November 2019 [Member]        
Debt Instrument [Line Items]        
Notes payable, interest rate 12.00% 12.00%    
Notes payable, maturity date Nov. 30, 2019 Nov. 30, 2019