Quarterly report pursuant to Section 13 or 15(d)

License Agreements (Details)

v3.8.0.1
License Agreements (Details) - USD ($)
 12 Months Ended
Aug. 14, 2017
Sep. 22, 2016
Dec. 31, 2013
Sep. 30, 2017
Dec. 31, 2016
Research and Development Arrangement, Contract to Perform for Others [Line Items]          
Proceeds from definitive agreement for the assignment of CERC 501 $ 25,000,000        
Escrowed cash receivable $ 3,750,000     $ 3,750,803 $ 0
Escrow deposit, term 12 months        
Milestone payment from definitive agreement for the assignment of CERC 501 $ 20,000,000        
Lilly | CERC-611          
Research and Development Arrangement, Contract to Perform for Others [Line Items]          
Initial license acquisition payments   $ 2,000,000      
Upfront payment due within 30 days   $ 750,000      
Term within execution of license agreement   30 days      
Upfront payment due after first subject dosed   $ 1,250,000      
Merck | CERC-301          
Research and Development Arrangement, Contract to Perform for Others [Line Items]          
Total initial payments     $ 1,500,000    
Additional payments     750,000    
Merck | CERC-301 | Research and development          
Research and Development Arrangement, Contract to Perform for Others [Line Items]          
Initial license acquisition payments     750,000    
Merck | COMTi          
Research and Development Arrangement, Contract to Perform for Others [Line Items]          
Initial license acquisition payments     $ 200,000