v3.19.1
Notes Payable - Schedule of Notes Payable (Detail) - USD ($)
Dec. 31, 2018
Nov. 30, 2018
Oct. 31, 2018
Jan. 31, 2018
Dec. 31, 2017
Debt Instrument [Line Items]          
Total face amount $ 9,117,000       $ 8,940,000
Less unamortized discount (1,780,000)     $ (271,000) (26,000)
Total carrying value 7,337,000       8,914,000
Amount classified as current 4,464,000       3,374,000
Amount classified as long-term 2,873,000       5,540,000
Class B Promissory Notes [Member]          
Debt Instrument [Line Items]          
Total face amount         100,000
Class C Promissory Notes [Member]          
Debt Instrument [Line Items]          
Total face amount         333,000
10% Promissory Note Due on Demand [Member]          
Debt Instrument [Line Items]          
Total face amount         500,000
8% Convertible Promissory Note Due March 2019 [Member]          
Debt Instrument [Line Items]          
Total face amount         250,000
8% Secured Promissory Notes Due July/August 2018 [Member]          
Debt Instrument [Line Items]          
Total face amount 250,000       1,350,000
8% Promissory Notes Due March 2019 [Member]          
Debt Instrument [Line Items]          
Total face amount         715,000
0% Promissory Notes Due May 2018 [Member]          
Debt Instrument [Line Items]          
Total face amount         261,000
8% Promissory Note Due March 2019 [Member]          
Debt Instrument [Line Items]          
Total face amount         200,000
8% Promissory Notes Due March 2019 [Member]          
Debt Instrument [Line Items]          
Total face amount         1,776,000
8% Secured Promissory Notes Due March 2019 [Member]          
Debt Instrument [Line Items]          
Total face amount         $ 3,455,000
0% Convertible Notes Due January 2021 [Member]          
Debt Instrument [Line Items]          
Total face amount 275,000        
4% Promissory Note Due April 2021 [Member]          
Debt Instrument [Line Items]          
Total face amount 847,000        
0% Promissory Note Due April 2019 [Member]          
Debt Instrument [Line Items]          
Total face amount 418,000        
8% Promissory Note Due March 2021 [Member]          
Debt Instrument [Line Items]          
Total face amount 2,107,000        
12% Convertible Notes Due October 2019 [Member]          
Debt Instrument [Line Items]          
Total face amount 4,000,000        
Less unamortized discount     $ (1,942,000)    
12% Convertible Notes Due November 2019 [Member]          
Debt Instrument [Line Items]          
Total face amount $ 1,220,000        
Less unamortized discount   $ (118,000)