Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Estimated Fair Value of Equity Securities Assumptions (Details)

v3.19.1
Fair Value Measurements - Estimated Fair Value of Equity Securities Assumptions (Details)
 3 Months Ended 12 Months Ended
Mar. 31, 2019
$ / shares
Dec. 31, 2018
Closing Common Stock Price [Member] | OTC exchange [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Valuation assumptions, measurement input, Closing common stock price $ 0.20  
Discount for Lack of Marketability [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Valuation assumptions, measurement input   35
Discount for Lack of Marketability [Member] | Tranche 1 [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Valuation assumptions, measurement input 24  
Discount for Lack of Marketability [Member] | Tranche 2 [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Valuation assumptions, measurement input 35  
Liquidity of Shares [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Valuation assumptions, measurement input term   1 year 5 months 12 days
Liquidity of Shares [Member] | Tranche 1 [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Valuation assumptions, measurement input term 1 year  
Liquidity of Shares [Member] | Tranche 2 [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Valuation assumptions, measurement input term 2 years  
Liquidation [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Valuation assumptions, measurement input   20
Near-term Sale [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Valuation assumptions, measurement input   5
Near-term Financing [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Valuation assumptions, measurement input   75