No definition available.

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- Definition

Cumulative amount of payments received under the collaborative arrangement as of the end of the reporting period.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Represents the maximum amount of payments receivable under the agreement.

+ References

No definition available.

+ Details

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- Definition

Represents the next potential milestone payment to be earned.

+ References

No definition available.

+ Details

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- Definition

Represents the next potential payment to be earned.

+ References

No definition available.

+ Details

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- Definition

Represents the number of drugs currently in clinical development under the collaboration agreement.

+ References

No definition available.

+ Details

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- Definition

Represents the number of Phase 2 studies in which the drug is being evaluated.

+ References

No definition available.

+ Details

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- Definition

Represents the number of active collaborations with the collaborative partner.

+ References

No definition available.

+ Details

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- Definition

Amount of deferred revenue recognized for transactions arising during the current reporting period. Deferred revenue is a liability as of the balance sheet date related to a revenue producing activity for which revenue has not yet been recognized. Generally, an Entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 13.A.4(a).Q1)
-URI http://asc.fasb.org/extlink&oid=27012821&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 13
-Section A

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Balance Type:	credit
Period Type:	duration

- Definition

The amount of consideration recognized during the period for the milestone or milestones.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 28
-Section 50
-Paragraph 2
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=51671726&loc=SL6892177-166501

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Collaborative Arrangements and Licensing Agreements, Strategic Partnership - Biogen (Nusinersen) (Details) - Biogen [Member] $ in Millions	1 Months Ended		3 Months Ended
	Apr. 30, 2016 USD ($)	Jan. 31, 2012 USD ($)	Mar. 31, 2016 USD ($) Agreement Drug Study
Collaborations and Licensing Agreements [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of strategic collaboration agreements \| Agreement			4
Collaborations and Licensing Agreements [Member] \| Drugs to Treat Neurological Disorders Under Collaborations [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of drugs currently in development \| Drug			6
Collaborations and Licensing Agreements [Member] \| Drugs to Treat Undisclosed Neurodegenerative Diseases [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of drugs currently in development \| Drug			3
Agreement Entered into in January 2012 [Member] \| Nusinersen [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Upfront payment recorded as deferred revenue		$ 29.0
Cumulative payments received			$ 150.0
Milestone payment earned			9.5
Next potential payment			75.0
Next prospective milestone			$ 60.0
Agreement Entered into in January 2012 [Member] \| Nusinersen [Member] \| Subsequent Event [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Milestone payment earned	$ 2.0
Agreement Entered into in January 2012 [Member] \| Nusinersen [Member] \| Phase 2 Studies in Infants and Children with SMA [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of Phase 2 studies in which drug is being evaluated \| Study			2
Agreement Entered into in January 2012 [Member] \| Nusinersen [Member] \| Phase 2 Studies in Infants with SMA [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of Phase 2 studies in which drug is being evaluated \| Study			1
Agreement Entered into in January 2012 [Member] \| Nusinersen [Member] \| Phase 2 Studies in Children with SMA [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of Phase 2 studies in which drug is being evaluated \| Study			1
Agreement Entered into in January 2012 [Member] \| Nusinersen [Member] \| License Fee and Substantive Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable			$ 346.0
Agreement Entered into in January 2012 [Member] \| Nusinersen [Member] \| Development Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable			121.0
Agreement Entered into in January 2012 [Member] \| Nusinersen [Member] \| Regulatory Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable			$ 150.0