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Collaborative and Other Relationships - Alkermes (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Collaborative arrangements and non-collaborative arrangement transactions
Research and development		$ 3,990.9	$ 2,280.6	$ 2,597.2
Potential future milestone payments commitment to third party approximately		10,200.0
Alkermes
Collaborative arrangements and non-collaborative arrangement transactions
Research and development		$ 32.4	53.5	$ 68.7
Potential future milestone payments commitment to third party approximately			$ 155.0
VUMERITY | Alkermes
Collaborative arrangements and non-collaborative arrangement transactions
Percentage of royalties as per collaboration	15.00%	15.00%
Royalties payable period, post FDA approval		5 years

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- Definition

Percentage of royalties as per collaboration.

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Potential future milestone payments commitment to third party approximately.

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Royalties Payable Period, Post FDA Approval

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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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- Definition

The costs incurred in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, excluding in-process research and development acquired in a business combination consummated during the period. Excludes software research and development, which has a separate concept.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 730
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6420194&loc=d3e21568-108373

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