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.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

The maximum amount of payments receivable for commercialization milestones under the collaboration agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
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- Definition

The maximum amount of payments receivable for development milestones under the collaboration agreement.

+ References

No definition available.

+ Details

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- Definition

The maximum amount of payments receivable for license fees and substantive milestones under the collaboration agreement.

+ References

No definition available.

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

The amount of payments received during the period for advancing programs under the collaboration agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The number of new performance obligations identified under the collaboration agreement.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
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- Definition

The number of separate performance obligations under the collaboration agreement.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
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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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Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The royalty percentage received on gross margins of drug(s) under the collaborative arrangement.

+ 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

- Definition

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.

+ References

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- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Collaborative Arrangements and Licensing Agreements, Bayer (Details) $ in Thousands	1 Months Ended		3 Months Ended		12 Months Ended
	Feb. 28, 2017 USD ($) PerformanceObligation	May 31, 2015 USD ($) PerformanceObligation	Dec. 31, 2019 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue					$ 1,122,599	$ 599,674	$ 514,179
R&D Revenue [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue					770,149	344,752	$ 394,165
Bayer [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of separate performance obligations \| PerformanceObligation	3
Revenue			$ 10,000
Deferred revenue			2,400		$ 2,400	$ 4,300
Bayer [Member] \| Revenue [Member] \| Strategic Partner [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Concentration percentage					1.00%	1.00%	13.00%
Bayer [Member] \| R&D Revenue [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue					$ 14,300	$ 5,000	$ 67,100
Bayer [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Upfront payment received		$ 100,000		$ 100,000
Maximum amount of payments receivable for license fees and milestones			385,000		385,000
Maximum amount of payments receivable for development milestones			125,000		125,000
Maximum amount of payments receivable for commercialization milestones			110,000		$ 110,000
Royalty percentage received on gross margins of both drugs combined					20.00%
Cumulative payments received			185,000		$ 185,000
Next prospective milestone			$ 20,000		$ 20,000
Number of separate performance obligations \| PerformanceObligation		3
Bayer [Member] \| R&D Services for IONIS-FXI-L [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Transaction price	$ 10,100
Bayer [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Upfront payment received	75,000
Payment received for advancing programs	$ 75,000
Number of new performance obligations \| PerformanceObligation	2
Transaction price	$ 75,000
Bayer [Member] \| IONIS-FXI-L [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of new performance obligations \| PerformanceObligation	1
Transaction price	$ 64,900
Bayer [Member] \| R&D Services for IONIS-FXI-L [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of new performance obligations \| PerformanceObligation	1