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Sale of Pelican Business and Investment in Primrose Bio - Narrative (Details) $ in Thousands		1 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended
	Sep. 18, 2023 USD ($) contract milestone shares	Jun. 30, 2024 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Jan. 01, 2025 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Noncurrent derivative assets	$ 3,200	$ 34,505	$ 34,505	$ 34,505		$ 3,531
Derivative Asset Noncurrent, Statement Of Financial Position, Extensible Enumeration, Not Disclosed Flag				condensed consolidated balance sheet
Gain on derivative instruments				$ 1,696	$ 0
Losses from equity method investment in Primrose Bio				(10,382)	$ 0
Primrose Bio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Impairment of equity method investment		5,800	5,800
Losses from equity method investment in Primrose Bio			(2,200)	(4,600)
Equity method investment in Primrose Bio				25,800
Primrose Bio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Consideration paid for an interest in potential development milestone	$ 15,000
Noncurrent derivative assets		$ 3,937	3,937	3,937		3,531
Primrose Bio \| PeliCRM197 \| Forecast
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Sales revenue milestone							$ 3,000
Primrose Bio \| Below 3 million \| PeliCRM197 \| Forecast
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Interest in sales revenue (as a percent)							25.00%
Primrose Bio \| Above 3 million \| PeliCRM197 \| Forecast
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Interest in sales revenue (as a percent)							35.00%
Agenus Partnered Program
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Percentage of milestones (as a percent)	50.00%
Agenus Partnered Program \| Primordial Genetics
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Number of contracts \| contract	2
Gain on derivative instruments			$ 200	$ 400
Number of milestones (milestone) \| milestone	2
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| Pelican Technology Holdings, Inc.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Consideration paid for an interest in potential development milestone	$ 15,000
Goodwill written off						4,100
Gain on sale of Pelican						$ 2,100
Business exit costs	$ 1,200
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| Pelican Technology Holdings, Inc. \| Restricted Stock Awards
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Shares received as consideration (in shares) \| shares	474,746
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| Pelican Technology Holdings, Inc. \| Common Stock
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Shares received as consideration (in shares) \| shares	2,146,957
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| Pelican Technology Holdings, Inc. \| Preferred Stock
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Shares received as consideration (in shares) \| shares	4,278,293