The number of agreements entered into with the collaboration partner.

No definition available.

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- Definition

The number of performance obligations at the inception of a contract.

+ References

No definition available.

+ Details

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- Definition

The number of separate performance obligations under the collaboration agreement.

+ References

No definition available.

+ Details

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- Definition

The amount of consideration the Company earned or is eligible to earn under the collaboration agreement, including any variable consideration.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

The additional amount of consideration the Company earned under the collaboration agreement that is added to the transaction price.

+ References

No definition available.

+ Details

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- Definition

The amount of upfront payments received during the period under the collaboration agreement.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

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- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

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- Details

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- Details

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Significant Accounting Policies, Revenue Recognition (Details) $ in Thousands	1 Months Ended			3 Months Ended					6 Months Ended
	Apr. 30, 2021 USD ($)	Feb. 28, 2017 USD ($) PerformanceObligation	May 31, 2015 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2018 USD ($)	Jun. 30, 2018 Agreement	Jun. 30, 2021 USD ($) PerformanceObligation	Jun. 30, 2020 USD ($)
Revenue Recognition [Abstract]
Number of performance obligations at inception of contract \| PerformanceObligation									1
Revenue				$ 125,750		$ 145,537			$ 237,357	$ 278,905
Biogen [Member]
Revenue Recognition [Abstract]
Number of agreements \| Agreement								2
Biogen 2013 Strategic Neurology [Member] \| ION541 [Member]
Revenue Recognition [Abstract]
Revenue	$ 10,000			$ 10,000
IONIS-FB-L for Complement-Mediated Diseases [Member]
Revenue Recognition [Abstract]
Upfront payment received							$ 75,000
Biogen 2018 Strategic Neurology [Member]
Revenue Recognition [Abstract]
Milestone payment received and added to transaction price					$ 7,500
AstraZeneca [Member] \| ION455 [Member]
Revenue Recognition [Abstract]
Revenue					$ 30,000
Bayer [Member]
Revenue Recognition [Abstract]
Upfront payment received			$ 100,000
Bayer [Member]
Revenue Recognition [Abstract]
Upfront payment received		$ 75,000
Number of separate performance obligations \| PerformanceObligation		3
Transaction price		$ 75,000