No definition available.

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- Definition

Cumulative amount of payments received under the collaboration agreement as of the end of the reporting period.

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No definition available.

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The next potential milestone payment to be earned under the collaboration agreement.

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No definition available.

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- Definition

The number of drugs in clinical development to treat neurodegenerative diseases under the collaboration agreement.

+ References

No definition available.

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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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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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Revenue earned during the period from the leasing or otherwise lending to a third party the entity's rights or title to certain property. Royalty revenue is derived from a percentage or stated amount of sales proceeds or revenue generated by the third party using the entity's property. Examples of property from which royalties may be derived include patents and oil and mineral rights.

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Collaborative Arrangements and Licensing Agreements, Biogen (Details) $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended
	Jul. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) Drug	Jun. 30, 2016 USD ($)
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue earned		$ 104,152		$ 38,470	$ 214,456	$ 75,345
SPINRAZA royalties		22,366		0	$ 27,577	0
Collaboration Agreements with Biogen [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of drugs in clinical development to treat neurodegenerative diseases \| Drug					5
Revenue earned		79,100		$ 9,400	$ 99,400	$ 30,700
Milestone payment earned			$ 5,000
Deferred revenue		$ 52,100			$ 52,100
Collaboration Agreements with Biogen [Member] \| Revenue [Member] \| Strategic Partner [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Concentration percentage		76.00%		25.00%	46.00%	41.00%
Collaboration Agreements with Biogen [Member] \| Minimum [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Cumulative payments received		$ 560,000			$ 560,000
SPINRAZA [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
SPINRAZA royalties					27,577
Milestone payment earned		50,000
Next prospective milestone		40,000			40,000
Strategic Neurology [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Next prospective milestone		$ 2,000			$ 2,000
Strategic Neurology [Member] \| Subsequent Event [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Milestone payment earned	$ 10,000