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

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Represents the maximum amount of payments receivable per drug under the agreement.

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No definition available.

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Represents the period from the inception of the collaboration during which a change of control could result in the entity being required to refund the upfront payment received.

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No definition available.

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Represents the next prospective milestone payment to be earned.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets 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.

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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.

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

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Collaborative Arrangements and Licensing Agreements, Traditional Pharmaceutical Alliances and Licensing - Biogen Idec (Strategic Neurology) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Apr. 30, 2015	Sep. 30, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue earned			$ 49,121	$ 44,063	$ 232,133	$ 129,300
Biogen Idec [Member] \| Collaborations and Licensing Agreements [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue earned			18,100	$ 31,700	75,100	$ 76,400
Deferred revenue			$ 98,100		$ 98,100
Biogen Idec [Member] \| Collaborations and Licensing Agreements [Member] \| Revenue [Member] \| Strategic Partner [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Concentration percentage			37.00%		32.00%
Biogen Idec [Member] \| Agreement Entered into in September 2013 [Member] \| Strategic Neurology [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Upfront fee recorded as deferred revenue		$ 100,000
Period during which a change in control could result in requirement to refund upfront payment					6 years
Cumulative payments received			$ 135,000		$ 135,000
Milestone payment earned	$ 10,000
Biogen Idec [Member] \| Agreement Entered into in September 2013 [Member] \| Strategic Neurology [Member] \| Maximum [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Next prospective milestone			10,000		10,000
Biogen Idec [Member] \| Agreement Entered into in September 2013 [Member] \| Strategic Neurology [Member] \| Antisense Drug for Neurological Disease [Member] \| License Fee and Substantive Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payment receivable per drug			260,000		260,000
Biogen Idec [Member] \| Agreement Entered into in September 2013 [Member] \| Strategic Neurology [Member] \| Antisense Drug for Neurological Disease [Member] \| Research and Development Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payment receivable per drug			60,000		60,000
Biogen Idec [Member] \| Agreement Entered into in September 2013 [Member] \| Strategic Neurology [Member] \| Antisense Drug for Neurological Disease [Member] \| Regulatory Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payment receivable per drug			130,000		130,000
Biogen Idec [Member] \| Agreement Entered into in September 2013 [Member] \| Strategic Neurology [Member] \| Other Modalities [Member] \| Pre-specified Events [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payment receivable per drug			90,000		90,000
Biogen Idec [Member] \| Agreement Entered into in September 2013 [Member] \| Strategic Neurology [Member] \| Other Modalities [Member] \| Research and Development Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payment receivable per drug			35,000		35,000
Biogen Idec [Member] \| Agreement Entered into in September 2013 [Member] \| Strategic Neurology [Member] \| Other Modalities [Member] \| Regulatory Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payment receivable per drug			$ 55,000		$ 55,000