Quarterly report pursuant to Section 13 or 15(d)

Borrowings - Additional Information (Details)

v3.19.2
Borrowings - Additional Information (Details)
6 Months Ended 12 Months Ended
Nov. 02, 2018
$ / shares
Jun. 30, 2019
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
FinancingArrangement
Jan. 01, 2019
USD ($)
Installment
Oct. 26, 2017
USD ($)
Debt Instrument [Line Items]            
Reverse stock split   15-to-1        
Reverse stock split ratio 0.0667          
Long-term debt   $ 13,682,000        
Other Financing Arrangements            
Debt Instrument [Line Items]            
Number of financing arrangements | FinancingArrangement       3    
Debt instrument, face amount       $ 472,000    
Long-term debt   99,000 $ 238,000      
Debt instrument, discount   388,000        
Other Financing Arrangement One            
Debt Instrument [Line Items]            
Debt instrument, maturity date       2020-06    
Other Financing Arrangement Two            
Debt Instrument [Line Items]            
Debt instrument, maturity date       2020-08    
Loan and Security Agreement | East West Bank            
Debt Instrument [Line Items]            
Maximum borrowings available   $ 8,000,000        
Line of credit facility, interest rate during period   1.00%        
Line of credit facility, maturity date   2019-11        
Remaining borrowing capacity   $ 8,000,000 8,000,000      
Subordinated Term Loan and Security Agreement | B. Riley Principal Investments, LLC            
Debt Instrument [Line Items]            
Maximum borrowings available     12,000,000     $ 10,000,000
Minimum principal amount outstanding to have waiver of defined prepayment penalties     $ 10,000,000      
Debt instrument, stated interest rate     10.00%      
Line of credit facility, maturity date     Sep. 01, 2022      
Outstanding borrowings   12,000,000 $ 12,000,000      
Total accrued interest   1,109,000 1,001,000      
Debt instrument, convertible, price of common stock per share | $ / shares $ 8.87          
Subordinated Term Loan and Security Agreement | B. Riley Principal Investments, LLC | Prior to First Anniversary of Effective Date            
Debt Instrument [Line Items]            
Designated percentage 100.00%          
Subordinated Term Loan and Security Agreement | B. Riley Principal Investments, LLC | Year Two of Loan Agreement            
Debt Instrument [Line Items]            
Designated percentage 75.00%          
Subordinated Term Loan and Security Agreement | B. Riley Principal Investments, LLC | Year Three of Loan Agreement            
Debt Instrument [Line Items]            
Designated percentage 50.00%          
Subordinated Term Loan and Security Agreement | B. Riley Principal Investments, LLC | Year Four of Loan Agreement            
Debt Instrument [Line Items]            
Designated percentage 25.00%          
Subordinated Term Loan and Security Agreement | B. Riley Principal Investments, LLC | Final Year of Agreement on or Prior to Maturity Date            
Debt Instrument [Line Items]            
Designated percentage 12.50%          
Promissory Notes Payable            
Debt Instrument [Line Items]            
Debt instrument, outstanding balance   $ 582,000 $ 718,000   $ 736,000  
Debt instrument, periodic payment, number of equal quarterly installments | Installment         20  
Debt instrument, frequency of periodic payment   quarterly        
Promissory Notes Payable | Minimum            
Debt Instrument [Line Items]            
Debt instrument, payment term   2 years        
Promissory Notes Payable | Maximum            
Debt Instrument [Line Items]            
Debt instrument, stated interest rate   8.00%        
Debt instrument, payment term   4 years