v3.19.1
Notes Payable to Related Parties - Schedule of Notes Payable to Related Parties (Detail) - USD ($)
Dec. 31, 2018
Jan. 31, 2018
Dec. 31, 2017
Notes Payable to Related Parties [Line Items]      
Total face amount $ 9,117,000   $ 8,940,000
Less unamortized discount $ (1,780,000) $ (271,000) (26,000)
Total carrying value     3,756,000
Amount classified as current     441,000
Amount classified as long-term     3,315,000
Class B Promissory Notes [Member]      
Notes Payable to Related Parties [Line Items]      
Total face amount     100,000
Class C Promissory Notes [Member]      
Notes Payable to Related Parties [Line Items]      
Total face amount     333,000
8% Secured Promissory Notes Due 3/31/19 [Member]      
Notes Payable to Related Parties [Line Items]      
Total face amount     3,455,000
Notes Payable to Related Parties [Member]      
Notes Payable to Related Parties [Line Items]      
Total face amount     3,992,000
Less unamortized discount     (236,000)
Notes Payable to Related Parties [Member] | Class B Promissory Notes [Member]      
Notes Payable to Related Parties [Line Items]      
Total face amount     200,000
Notes Payable to Related Parties [Member] | Class C Promissory Notes [Member]      
Notes Payable to Related Parties [Line Items]      
Total face amount     667,000
Notes Payable to Related Parties [Member] | 0% Promissory Note Due 3/31/19 [Member]      
Notes Payable to Related Parties [Line Items]      
Total face amount     44,000
Notes Payable to Related Parties [Member] | 8% Secured Promissory Notes Due 3/31/19 [Member]      
Notes Payable to Related Parties [Line Items]      
Total face amount     1,050,000
Notes Payable to Related Parties [Member] | 8% Promissory Notes Due 3/31/19 [Member]      
Notes Payable to Related Parties [Line Items]      
Total face amount     $ 2,031,000