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Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details) shares in Millions | 3 Months Ended | 6 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | --- | ---
Sep. 30, 2025 USD ($) contract position shares | Sep. 30, 2024 USD ($) shares | Jun. 30, 2025 USD ($) | Sep. 30, 2025 USD ($) segment contract position shares | Sep. 30, 2024 USD ($) shares | Dec. 31, 2024 USD ($) | Jan. 31, 2010 cvr
Property, Plant and Equipment |  |  |  |  |  |  |
Number of operating segments | segment |  |  |  | 1 |  |  |
Number of reportable segments | segment |  |  |  | 1 |  |  |
Gain on sale of Pelthos business |  |  |  | $ 53,072,000 | $ 0 |  |
Revenue recognized that was previously deferred | $ 0 | $ 200,000 |  | $ 600,000 | $ 1,200,000 |  |
Sale of viking common stock (in shares) | shares | 0.0 | 0.0 |  | 0.0 | 0.7 |  |
Gain on sale of viking common stock |  |  |  |  | $ 60,000,000 |  |
Number of positions in an unrealized loss position | position | 73 |  |  | 73 |  |  |
Unrealized losses | $ (170,000) |  |  | $ (170,000) |  |  |
Credit losses related to available-for-sale debt securities | 0 | $ 0 |  | 0 | 0 |  |
Amortized cost |  |  |  |  | 50,000.00 |  |
Increase (decrease) in allowance for credit losses | 300,000 | (200,000) |  | 400,000 | (300,000) |  |
Inventory write-down | 0 | 100,000 |  | 0 | 200,000 |  |
Inventory | 11,900,000 |  |  | 11,900,000 |  | $ 14,114,000 |
Fair value adjustments to partner program derivatives | 833,000 | (7,812,000) |  | 0 | (7,812,000) |  |
Loss from equity method investment in Primrose Bio |  |  |  | 0 | 5,763,000 |  |
Equity method investments | 42,000,000 |  |  | 42,000,000 |  | $ 0 |
Observable price changes | $ 0 | (30,000.00) |  | $ 0 | (25,790,000) |  |
Agenus Warrant |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Fair value adjustments to partner program derivatives |  | (8,000,000) |  |  | (6,800,000) |  |
Primrose mRNA |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Investment owned, net assets, percentage | 31.50% |  |  | 31.50% |  | 31.40% |
Loss from equity method investment in Primrose Bio |  | 1,200,000 |  |  | 5,800,000 |  |
Equity method investments |  |  |  |  |  | $ 0 |
Impairment of equity method investment | $ 0 |  |  | $ 0 | (5,800,000) |  |
Vikings |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Fair value adjustments to partner program derivatives |  | (7,900,000) |  |  | 7,300,000 |  |
Performance Shares |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Performance period for awards (in years) |  |  |  | 3 years |  |  |
Metabasis Therapeutics |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Number of contingent value rights issued | cvr |  |  |  |  |  |  | 4
Minimum | Performance Shares |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Payout range (as a percent) |  |  |  | 0.00% |  |  |
Maximum | Performance Shares |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Payout range (as a percent) |  |  |  | 200.00% |  |  |
Partner Programs |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Fair value adjustments to partner program derivatives | $ (700,000) |  |  | $ (100,000) |  |  |
Agenus Partnered Program | Primordial Genetics |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Number of contracts | contract | 2 |  |  | 2 |  |  |
Agenus Bot/Bal |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Fair value adjustments to partner program derivatives |  | $ (7,200,000) | $ (500,000) |  |  |  |
Primrose mRNA |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Fair value adjustments to partner program derivatives |  |  | (600,000) |  | $ (600,000) |  |
Castle Creek Investment |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Fair value adjustments to partner program derivatives |  |  | $ 300,000 |  |  |  |
Limbach Holdings, Inc |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Gain on sale of Pelthos business | $ 53,100,000 |  |  | $ 53,100,000 |  |  |
Captisol |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Inventory | $ 2,300,000 |  |  | $ 2,300,000 |  | $ 3,100,000 |
Primrose mRNA |  |  |  |  |  |  |
Property, Plant and Equipment |  |  |  |  |  |  |
Percentage of milestones (as a percent) | 50.00% |  |  | 50.00% |  |  |

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