v3.26.1
Net Income (Loss) Per Share (Schedule of Basic And Diluted Net Income (Loss) Per Share) (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Amounts used for basic and diluted per share calculations:    
Net income (loss) attributable to Agenus Inc. common stockholders $ 39,172 $ (25,320)
Weighted average number of Agenus Inc. common shares outstanding - basic 37,941 24,469
Effect of potentially dilutive securities:    
Share based compensation awards 341 0
Warrants 3 0
Weighted average number of Agenus Inc. common shares outstanding - diluted 38,285 24,469
Net income (loss) attributable to Agenus Inc. per common share:    
Basic $ 1.03 $ (1.03)
Diluted $ 1.02 $ (1.03)