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Fair Value Measurements - Narrative (Details)	12 Months Ended
Fair Value Measurements - Narrative (Details)	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Oct. 31, 2025 USD ($)	Jun. 30, 2025 USD ($)	Jul. 02, 2024 USD ($)
Business Combination, Contingent Consideration [Line Items]
Impairment of ROU asset	$ 0	$ 0
Contingent consideration obligations	$ 246,400,000	221,600,000
Contingent consideration obligations		$ 291,200,000
Human Immunology Biosciences
Business Combination, Contingent Consideration [Line Items]
Contingent consideration obligations					$ 205,800,000
Contingent consideration obligations					$ 279,300,000
Human Immunology Biosciences \| Maximum \| Phase 3 Clinical Trial, Felzartamab AMR
Business Combination, Contingent Consideration [Line Items]
Contingent consideration obligations				$ 150,000,000.0
Human Immunology Biosciences \| Maximum \| Phase 3 Clinical Trial, Felzartamab IgAN
Business Combination, Contingent Consideration [Line Items]
Contingent consideration obligations			$ 150,000,000.0
Human Immunology Biosciences \| Measurement Input, Probability Rate
Business Combination, Contingent Consideration [Line Items]
Discount rate					0.670
Human Immunology Biosciences \| Measurement Input, Probability Rate \| Maximum
Business Combination, Contingent Consideration [Line Items]
Discount rate	0.950
Human Immunology Biosciences \| Measurement Input, Probability Rate \| Minimum
Business Combination, Contingent Consideration [Line Items]
Discount rate	0.700