Quarterly report pursuant to Section 13 or 15(d)

Joint Venture Agreement - Additional Information (Details)

v3.19.3
Joint Venture Agreement - Additional Information (Details) - USD ($)
3 Months Ended 9 Months Ended 77 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Dec. 31, 2018
May 31, 2013
Schedule of Equity Method Investments [Line Items]              
Joint venture net loss     $ 0 $ 4,000      
Earn-Out from siParadigm, current portion $ 693,000   693,000   $ 693,000 $ 0  
Research and Development              
Schedule of Equity Method Investments [Line Items]              
Joint venture net loss 0 $ 1,000 0 $ 4,000      
Equity Method Investee              
Schedule of Equity Method Investments [Line Items]              
Earn-Out from siParadigm, current portion $ 10,000   $ 10,000   10,000    
Joint Venture Agreement              
Schedule of Equity Method Investments [Line Items]              
Percentage of outstanding membership interests in joint venture (percent)             50.00%
Investment in joint venture         $ 2,000,000    
Fair value of capital contribution in joint venture             $ 6,000,000
Maximum | Joint Venture Agreement              
Schedule of Equity Method Investments [Line Items]              
Required payments to acquire interest in joint venture             $ 6,000,000