No definition available.

Name:	ions_CollaborativeArrangementAndLicensingAgreementAbstract
Namespace Prefix:	ions_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Cumulative amount of milestone payments, license fees and/or upfront fees received under the collaborative arrangement as of the end of the reporting period.

+ References

No definition available.

+ Details

Name:	ions_CumulativePaymentsAndOrFeesReceived
Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the maximum amount of payments receivable under the agreement.

+ References

No definition available.

+ Details

Name:	ions_MaximumAmountOfPaymentsReceivable
Namespace Prefix:	ions_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the next potential milestone payment to be earned.

+ References

No definition available.

+ Details

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

- 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
-Topic 605
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 13.A.4(a).Q1)
-URI http://asc.fasb.org/extlink&oid=27012821&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 13
-Section A

+ Details

Name:	us-gaap_DeferredRevenueAdditions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 28
-Section 50
-Paragraph 2
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=51671726&loc=SL6892177-166501

+ Details

Name:	us-gaap_RevenueRecognitionMilestoneMethodRevenueRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_CounterpartyNameAxis=ions_BiogenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=ions_CollaborativeArrangementJune2012Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=ions_IONISDMPK25Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ions_AchievementOfMilestoneAxis=ions_LicenseAndSubstantiveMilestonesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ions_AchievementOfMilestoneAxis=ions_DevelopmentMilestonesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ions_AchievementOfMilestoneAxis=ions_RegulatoryMilestonesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=ions_AgreementAmendedInJune2015Member
Namespace Prefix:
Data Type:	na
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Collaborative Arrangements and Licensing Agreements, Strategic Partnerships - Biogen (IONIS-DMPK-2.5) (Details) - Biogen [Member] - USD ($) $ in Millions	1 Months Ended
	Nov. 30, 2015	Jun. 30, 2012	Dec. 31, 2015
Agreement Entered into in June 2012 [Member] \| IONIS-DMPK-2.5 [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Upfront fee recorded as deferred revenue		$ 12.0
Next potential milestone			$ 35.0
Agreement Entered into in June 2012 [Member] \| IONIS-DMPK-2.5 [Member] \| License Fee and Substantive Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable			263.0
Cumulative payments and/or fees received			39.0
Agreement Entered into in June 2012 [Member] \| IONIS-DMPK-2.5 [Member] \| Development Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable			63.0
Agreement Entered into in June 2012 [Member] \| IONIS-DMPK-2.5 [Member] \| Regulatory Milestones [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable			130.0
Agreement Amended in June 2015 [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Milestone payment earned	$ 2.8
Agreement Amended in June 2015 [Member] \| IONIS-DMPK-2.5 [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable			4.2
Next potential milestone			$ 1.4