Quarterly report pursuant to Section 13 or 15(d)

Description of Business - Textual (Details)

v3.19.3
Description of Business - Textual (Details) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 9 Months Ended
Jun. 30, 2019
Dec. 31, 2018
Mar. 31, 2019
Sep. 30, 2019
Sep. 30, 2018
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]          
Issuance costs       $ 0 $ 180
Proceeds from issuance of common stock in connection with private placement       $ 50,000 $ 0
Private Placement [Member]          
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]          
Shares issued (in shares) 3,048,780        
Price per share (in dollars per share) $ 16.40        
Issuance costs $ 100        
Proceeds from issuance of common stock in connection with private placement $ 49,900        
Nestec Ltd. (Nestle Health Sciences) [Member] | CDX-6114 [Member] | Collaborative Arrangement [Member]          
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]          
Milestone payment amount   $ 1,000      
Duration to pay after milestone achievement (in days)   60 days      
Event of counterparty exercising alternative option     $ 3,000