Notice period to terminate a collaborative arrangement.

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- Definition

Future milestone payments that could be paid upon achievement of certain milestones per agreement.

+ References

No definition available.

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- Definition

n/a

+ References

No definition available.

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- Definition

The period of time from the first commercial sale of each licensed product that the license will expire if the period is later than the expiration, lapse, abandonment or invalidation of the last valid claim of the licensed intellectual property to expire, lapse or become abandoned or unenforceable in all countries of the world.

+ References

No definition available.

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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
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-Section S99
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- Definition

The aggregate costs incurred (1) 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 (2) 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, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-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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-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

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Collaboration and License Agreements - Rhett and ALS (Details) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
	Jun. 07, 2017	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
NCH Rett and ALS
Research and development expenses			$ 150,391	$ 58,892	$ 27,493
Regenx Rett and ALS license \| ReGenX
RegenXBio Rett and ALS
Period of time from the first commercial sale of each licensed product that the license will expire if that date is later than the expiration, lapse, abandonment or invalidation of the last valid claim of the licensed intellectual property to expire, lapse or become abandoned or unenforceable in all countries of the world	7 years
Regenx Rett and ALS license \| ReGenX \| Maximum
RegenXBio Rett and ALS
Potential milestone payments to be paid	$ 36,000
Regenx Rett and ALS license \| Up-front Payment Arrangement [Member] \| ReGenX
RegenXBio Rett and ALS
Up-front payment made	$ 6,000
NCH Licenses \| NCH
NCH Rett and ALS
Research and development expenses				$ 300
NCH Licenses \| NCH \| After Second Anniversary Of License Effective Date
NCH Rett and ALS
Period of prior written notice to terminate agreement		6 months
NCH Licenses \| NCH \| Upon Other Party's Material Breach of License Not Cured Within Specified Period
NCH Rett and ALS
Period of prior written notice to terminate agreement		90 days