Amortization and Impairment of Acquired Intangible Assets

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- Definition

Finite-Lived Intangible Asset, Weighted-Average Remaining Useful Life

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Amount of amortization expense for finite-lived intangible asset. Excludes goodwill and capitalized cost for software to be sold, leased, or marketed.

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- Definition

Amount of identifiable finite-lived intangible asset acquired in business combination and recognized at acquisition date.

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- Definition

Useful life of finite-lived intangible asset, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Excludes goodwill and capitalized cost for software to be sold, leased, or marketed.

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- Definition

Amount of accumulated impairment loss for asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of impairment loss for indefinite-lived intangible asset. Excludes goodwill.

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Intangible Assets and Goodwill - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	May 14, 2026	Dec. 31, 2025
Goodwill [Line Items]
Amortization and impairment of acquired intangible assets	$ 172,800,000	$ 135,700,000	$ 477,500,000	$ 378,400,000
Impairment of intangible assets	0	0	0	3,500,000
Accumulated impairment losses related to goodwill	0		0
Amortization of intangible assets	172,800,000	$ 135,700,000	477,500,000	$ 374,900,000
SKYCLARYS
Goodwill [Line Items]
Amortization of intangible assets	45,200,000		45,200,000
Apellis Pharmaceuticals, Inc.
Goodwill [Line Items]
Amortization of intangible assets	$ 67,800,000		$ 67,800,000
Acquired and in-licensed rights and patents
Goodwill [Line Items]
Weighted-Average remaining useful life	13 years		13 years			13 years
In-process research and development \| Human Immunology Biosciences
Goodwill [Line Items]
Intangible assets	$ 1,600,000,000		$ 1,600,000,000
In-process research and development \| Apellis Pharmaceuticals, Inc.
Goodwill [Line Items]
Intangible assets	$ 32,300,000		$ 32,300,000		$ 32,300,000
Completed Technology \| Apellis Pharmaceuticals, Inc.
Goodwill [Line Items]
Intangible assets					4,630,000,000
Completed Technology \| Apellis Pharmaceuticals, Inc. \| EMPAVELI
Goodwill [Line Items]
Intangible assets					2,400,000,000
Completed Technology \| Apellis Pharmaceuticals, Inc. \| SYFOVRE
Goodwill [Line Items]
Intangible assets					1,900,000,000
Royalty and other revenue \| Apellis Pharmaceuticals, Inc. \| Sobi
Goodwill [Line Items]
Intangible assets					$ 380,000,000.0
Minimum
Goodwill [Line Items]
Estimated life (in years)	1 year		1 year			1 year
Maximum
Goodwill [Line Items]
Estimated life (in years)	30 years		30 years			30 years