Long-Term Obligations and Commitments, Royalty Revenue Monetization (Details) - Subsequent Event [Member] $ in Millions	1 Months Ended
Jan. 31, 2023 USD ($)
Royalty Revenue Monetization [Abstract]
Upfront payment received	$ 500
Maximum amount of payments receivable for additional milestones	625
SPINRAZA [Member]
Royalty Revenue Monetization [Abstract]
Maximum amount of annual sales on which royalty payments are paid	$ 1,500
SPINRAZA [Member] \| Minimum [Member]
Royalty Revenue Monetization [Abstract]
Percentage of royalty payments paid on annual sales of medicine	25.00%
Maximum royalty payments made before royalty interest reverts back	$ 475
SPINRAZA [Member] \| Maximum [Member]
Royalty Revenue Monetization [Abstract]
Percentage of royalty payments paid on annual sales of medicine	45.00%
Maximum royalty payments made before royalty interest reverts back	$ 550
Pelacarsen [Member]
Royalty Revenue Monetization [Abstract]
Percentage of royalty payments paid on annual sales of medicine	25.00%

The maximum amount of annual sales on which royalty payments are paid under the royalty purchase agreement.

No definition available.

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

The maximum amount of payments receivable for additional milestones under the royalty purchase agreement.

No definition available.

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

Maximum royalty payments under the royalty purchase agreement made before royalty interest reverts back to the Company.

No definition available.

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

The percentage of royalty payments paid on annual sales of medicine.

No definition available.

Name:	ions_PercentageOfRoyaltyPaymentsPaidOnAnnualSalesOfMedicine
Namespace Prefix:	ions_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

No definition available.

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

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

No definition available.

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

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ProductOrServiceAxis=ions_SpinrazaMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	srt_ProductOrServiceAxis=ions_PelacarsenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: