Quarterly report pursuant to Section 13 or 15(d)

Royalty Purchase Agreements (Details)

v3.19.1
Royalty Purchase Agreements (Details)
 3 Months Ended 12 Months Ended
Feb. 25, 2019
USD ($)
Agreement
Sep. 20, 2018
USD ($)
LicensedProduct
Mar. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Royalty Purchase Agreement [Line Items]        
Long-term royalty receivables     $ 15,375,000 $ 15,000,000 [1]
Changes in estimated fair value of contingent consideration     0  
Royalty Purchase Agreement [Member] | Agenus [Member]        
Royalty Purchase Agreement [Line Items]        
Payments to acquire milestones and royalties     15,000,000  
Long-term royalty receivables     15,000,000 15,000,000
Impairment related to long-term royalty receivable     0 $ 0
Royalty Purchase Agreement [Member] | Agenus [Member] | Silicon Valley Bank [Member]        
Royalty Purchase Agreement [Line Items]        
Loan borrowed     7,500,000  
Royalty Purchase Agreement [Member] | Agenus [Member] | Incyte [Member]        
Royalty Purchase Agreement [Line Items]        
Number of licensed products related to milestone and royalties | LicensedProduct   6    
Royalty Purchase Agreement [Member] | Agenus [Member] | Merck [Member]        
Royalty Purchase Agreement [Line Items]        
Number of licensed products related to milestone and royalties | LicensedProduct   1    
Royalty Purchase Agreement [Member] | Agenus [Member] | Incyte and Merck [Member]        
Royalty Purchase Agreement [Line Items]        
Purchased eligible milestone payments receivable upon achievement of potential development, regulatory and commercial milestones   $ 59,500,000    
Royalty Purchase Agreement [Member] | Agenus [Member] | Right to Receive Low-Single Mid-Teen Royalties [Member] | Incyte [Member]        
Royalty Purchase Agreement [Line Items]        
Purchased percentage of royalties on net sales of products   33.00%    
Purchased percentage of milestones   10.00%    
Royalty Purchase Agreement [Member] | Agenus [Member] | Right to Receive Low Single Digit Royalties [Member] | Merck [Member]        
Royalty Purchase Agreement [Line Items]        
Purchased percentage of royalties on net sales of products   33.00%    
Purchased percentage of milestones   10.00%    
Royalty Purchase Agreement [Member] | Bioasis Technologies Inc [Member]        
Royalty Purchase Agreement [Line Items]        
Payments to acquire milestones and royalties     300,000  
Long-term royalty receivables     400,000  
Impairment related to long-term royalty receivable     0  
Percentage of Option to purchase royalty right on future license agreements 1.00%      
Number of license agreements | Agreement 2      
Estimated fair value of contingent consideration     100,000  
Royalty Purchase Agreement [Member] | Bioasis Technologies Inc [Member] | Maximum [Member]        
Royalty Purchase Agreement [Line Items]        
Potential future cash payments     $ 200,000  
Royalty Purchase Second License Agreement [Member] | Bioasis Technologies Inc [Member] | Maximum [Member]        
Royalty Purchase Agreement [Line Items]        
Obligation upon exercise of options per licensed product $ 300,000      
Royalty Purchase Third License Agreement [Member] | Bioasis Technologies Inc [Member] | Maximum [Member]        
Royalty Purchase Agreement [Line Items]        
Obligation upon exercise of options per licensed product $ 400,000      
[1] The condensed consolidated balance sheet as of December 31, 2018 has been derived from the audited consolidated financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018.