Clinical Assets Acquired

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- Definition

Estimated additional payments upon achievement of development and commercial milestones.

+ References

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- Definition

Fair Value, Indefinite Lived Intangible Assets, Discount Rate

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No definition available.

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- Definition

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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No definition available.

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Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

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- Definition

Amount of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit, acquired at the acquisition date.

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- Definition

The expenses and losses recorded for each transaction with the acquiree that was recognized separately from the acquisition of assets and assumptions of liabilities in the business combination.

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- Definition

Amount of deferred tax liability attributable to taxable temporary differences from goodwill.

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- Definition

Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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- Definition

The cash outflow associated with other payments to acquire businesses including deposit on pending acquisitions and preacquisition costs.

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- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

The amount of purchased research and development assets that are acquired in a business combination have no alternative future use and are therefore written off in the period of acquisition.

+ References

No definition available.

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Acquisitions (Details)	1 Months Ended		12 Months Ended
Acquisitions (Details)	Mar. 31, 2020 USD ($)	Jun. 30, 2019 USD ($) product $ / shares	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Business Acquisition [Line Items]
Acquired in-process research and development			$ 18,000,000.0	$ 75,000,000.0	$ 0
BIIB118
Business Acquisition [Line Items]
Acquired in-process research and development	$ 75,000,000
Estimated additional payments upon achievement of development and commercial milestones	$ 635,000,000
Nightstar
Business Acquisition [Line Items]
Clinical assets acquired \| product		2
Price per share \| $ / shares		$ 25.50
Total transaction value		$ 847,600,000
Payments for pre-combination equity compensation		$ 4,600,000
Fair value, in-process research and development, discount rate		12.50%
Deferred tax liabilities, goodwill			60,900,000
Nightstar \| BIIB111
Business Acquisition [Line Items]
Intangible assets		$ 480,000,000
Intangible assets (excluding goodwill)			0
Nightstar \| BIIB112
Business Acquisition [Line Items]
Intangible assets		220,000,000
Intangible assets (excluding goodwill)			$ 0
Nightstar \| Post-acquisition equity compensation
Business Acquisition [Line Items]
Fair-value post-combination equity compensation		26,200,000
Nightstar \| Post-acquisition equity compensation \| Selling, general and administrative
Business Acquisition [Line Items]
Fair-value post-combination equity compensation		18,400,000
Nightstar \| Post-acquisition equity compensation \| Research and development
Business Acquisition [Line Items]
Fair-value post-combination equity compensation		$ 7,800,000